OpenVZ Pushing for Linux Kernel Inclusion

RomanianClimber writes to tell us News.com is reporting that SWSoft is trying to get OpenVZ into the Linux kernel. OpenVZ is an operating system level server virtualization solution, built on Linux. From the article: "In this, it has a major ally: Red Hat, the top seller of the open-source operating system, which plans to add the software to its free Fedora version of Linux for enthusiasts. The companies' move to make OpenVZ partitioning standard in Linux is timely, said Pund-IT analyst Charles King."

Comments

OpenVZ?

[Anonymous Coward]

The link is a buzzword-fest and it doesn't seem to have a wikipedia article. Anyone know what OpenVZ is?

Re:OpenVZ?

[Anonymous Coward]

A Slashdot article with no link to Wikipedia? What is the world coming to?

Maybe in your rush to be frist p0st, you missed out on the opportunity to find it yourself.

http://en.wikipedia.org/wiki/Virtual_private_serve r

Insightful? My ass.

Re:OpenVZ?

[Anonymous Coward]

first, highlight the word openvz. then right click, and select search the web for... then click the first link.

right smack bam in the middle of the page that was four obvious clicks away is your answer.

please note my condecending tone may vary with your browser. use firefox!

Re:OpenVZ?

[demon]

Other posts have covered it, but a quick summary:

OpenVZ is a subset of a commercial product called Virtuozzo. It provides "virtual private server" functionality similar to FreeBSD jail() or Solaris Zones, including a private virtual network stack, private process space, and such, to each instance. However, it all runs on top of a single (specially modified) Linux kernel. Its advantages are in easy resource sharing among instances - since everything is running under one kernel, resource sharing (disk, memory) is made simpler. However, it has the disadvantage of less isolation - if the kernel crashes or is subverted, the entire system is at risk. Also, unlike with Xen, for example, you can only run Linux distributions (with the same kernel version). You cannot run other OSes (like NetBSD, FreeBSD, etc.).

Re:OpenVZ?

[swv3752]

How exactly is that different from chroot system?

Re:OpenVZ?

[devovz]

It's much more secure: - root can get out of chroot, but root can't get out of VPS - chroot doesn't limit your resource usage anyhow (disk space, CPU, memory), in VPS you can dynamically change QoS parameters. - chroot doesn't limit processes anyhow on IPC, signals etc. f.e. user with UID=100 can SIGKILL processes run with the same UID. In VPSs you can have the same UIDs, but processes are isolated. - and so on...

Re:Don't forget...

[grub]

I salute you.

Why is this needed?

[Anonymous Coward]

You can compile anything you want into the kernel.

If this becomes part of the official kernel, then it becomes the kernel maintainer's problem.

If Red Hat comiles it into their distro's kernel, it is Red Hat's problem to maintain.

So if I were the kernel maintainer, I would need a very compelling reason to take on the extra work.

Re:Why is this needed?

[Anonymous Coward]

This is a normal problem. Even drivers have to have somebody to support them.

A few notes:
1. The kernel developers won't accept it without the vendor promising to help maintain it.
(see also: Figure out why many kernel developers have grown to hate Reiser and ReiserFSv3)

2. Redhat pays the salaries of a few kernel developers.
(see also; the massive amount of work Redhat-related items have already made it into the kernel and why everybody else that uses Linux (redhat or not) is better off for it.)

Re:Why is this needed?

[DShard]

1: hans?

2: Not just pay for but work with. This is the reason Xen has never really gotten into vanilla, even though it is supported directly by IBM, Intel and AMD.

Re:Why is this needed?

[m50d]

The kernel maintainers have as policy that they won't give you a stable source interface, if you want your driver to work well you should get it into the kernel (See Documentation/stable_api_nonsense.txt). That's fair enough, but a policy like that gives them a responsibility to accept things into the kernel.

Re:Why is this needed?

[zootm]

1: hans?

Best one-word argument I've seen in a while... if I had mod points right now...

Re:Why is this needed?

[vdboor]

The kernel maintainers have as policy that they won't give you a stable source interface, if you want your driver to work well you should get it into the kernel (See Documentation/stable_api_nonsense.txt). That's fair enough, but a policy like that gives them a responsibility to accept things into the kernel.

It's also their responsability to reject worse coded patches. Linus is known to refuse patches - no matter how sexy the feature is - until they have the quality he wants to see.

Re:Why is this needed?

[Anonymous Coward]

1. SWSoft maintains its code for years already. And will maintain ni future. It's the base of their product.
2. The same about developers. They do support on openvz.org, which is for free. I saw some fixes/patches in LKML, etc.

Re:Why is this needed?

[michelcultivo]

And where is the problem?

Re:Why is this needed?

[pyite69]

> You can compile anything you want into the kernel.

Kernel hacks that aren't part of Linus' kernel are a nightmare to maintain over time. At one point my machine had a PPTP hack, a hack for my HDTV card, and a hack for my video card. Upgrading kernels was a nightmare.

A project isn't complete until it is easily usable by the major distros (debian especially). This means getting into the kernel, or X, or whatever projects are affected. Not easy sometimes unfortunately.

Anyone worried?

[paulius_g]

Now, I've seen SW-Soft at work numerous reasons and I don't quite agree with their principles of development. Just check out their forums, they have an awesome community of people asking features in their higer end products and they never want to implement those. Instead, they're creating some kinds of "solution" to allow "lower TCO" and "easier management", at an extra cost of course. I've used their software, and it's quite buggy.

Now, Virtuozzo is one of their most awesome products, but I still don't feel right about having a company control over a piece of software embedded into a kernel. I have a chilly feeling about what they might do next and about what they're actually gaining by enabling this.

Just my two cents, I'm sure I'll get many replies of people disagreeing.

Re:Anyone worried?

[slavemowgli]

No, I'm not worried. If the product is as crappy/buggy as you describe, Linus won't merge it.

Re:Anyone worried?

[Anonymous Coward]

While over the past year I've come to the conclusion that HSPComplete is a Complete Disaster, I've yet to find anything terribly irritating about Virtuozzo. It runs well. Of course, I'm probably biased, having had to deal with that other piece of software that SWSoft wrote while drunk, but I haven't seen a massive amount of bugs with Virtuozzo itself.

The fun part is, they're talking OpenVZ. OpenVZ can't truly be controlled by a company, otherwise, it isn't 'open'. If it ain't open, it ain't going in the kernel.

My only chilling feelings are for the company itself. While presently, if you want to run a serious business, you need to shell out the money to SWSoft for Virtuozzo (sans Open), that's so obviously going to change when the Open Source community hits OpenVZ. ;)

Re:Anyone worried?

[Bogtha]

I still don't feel right about having a company control over a piece of software embedded into a kernel.

If Linus merges it into his tree, then how are they the ones that control it? If Redhat merge it into their tree, then how are they the ones that control it?

The whole point of Free Software is that the user is the one in control, not whoever happens to hold the copyright.

You do realise that other companies have lots of code in the kernel already, don't you? This is by no means the first company to push to have their code included in the kernel. SGI contributed XFS. IBM contributed JFS. Namesys contributed ReiserFS and are currently pushing to have Reiser4 included.

I have a chilly feeling about what they might do next and about what they're actually gaining by enabling this.

Some pretty decent reasons for this off the top of my head are:

1. They have less maintenance work to do (no updates every time a new kernel comes out).
2. Less hassle for their users.
3. More testers/bugfixers.
4. They gain positive publicity.

Why the FUD?

Re:Anyone worried?

[Hiro Antagonist]

I'd like to post my agreement; VZ is generally a massive pile, is a resource hog extrodinare, and sucks royally compared to both Linux VServers and FreeBSD jails. HSPComplete is even uglier. I mean, the vzbackup scripts require SSH, even if you're using them to backup the local machine, and they have this nasty habit of locking on a random VPS and then dying silently.

Re:Anyone worried?

[Tim C]

The whole point of Free Software is that the user is the one in control

Going wildly offtopic for a moment, that may be the *intention*, but it's not generally the case. In practice, if the user is a developer who is skilled in the relevant area, then they are in control - they can hack bits in and/or out to their heart's content.

Where the user is not skilled in the appropriate area, or is semi- or non-technical, they have no more control than they do with any other OS. They can tweak settings here and there, and that's it. For everything else (patches, new features, etc) they must rely on a third party, most likely the software vendor.

Apart from that, I agree with you. Just because a company contribute code to the kernel, doesn't mean they control anything. They can't take it away again at a later date, and (assuming the maintiner is awake) they can't slip malicious features in either. At worst, they can cease development of the free version, at which point we either pick up the slack, replace it, or just do without.

Re:Anyone worried?

[Toshio]

Not only that, but they sometimes actively prevent interested people from buying their products. I'm in a company that is placed three hour drive from Munchen and one hour from Venice, and they insist we do business with them through their Moscow office... Because they think Moscow is somehow closer to me. Three timezones of difference and the only link being 4 hour flight from Frankfurt/Main are somehow closer than 30 minute plane flight to Frankfurt/M. Strange though, that they didn't recommend Novosibirsk offce, that would be just lovely. I just love that place early in the winter. It is so romantic to be out in a snow at -40C. The irony is that their Darmstadt office is closer to Moscow, than my company is.

E-mail didn't help, fax didn't help, and phone didn't help to change their mind about it. I almost sat in the plane and spend an afternoon to visit them in Darmstadt to complain to them in person, but stopped thinking why should I do that. Why should I pay 100, just to tell them I'm interested in buying 60,000 worth of licenes for their products. If they don't want to sell to me, then I certainly won't be begging them to allow me to buy their products. At the end we have struck a sweet deal with VMware, and I'm so satisfied with attitude, support & community at VMware, that I never look back wondering, what if...

Not being one of their customers, I can't really comment on the level of their customer support, but with attitude like SW-Soft has, I don't think its much. If they dislike the paying custmers as much as you say, then I don't think they will have any more respect of free ones either. Personally, I wouldn't even think about touching anything of theirs again. They're arrogant, they can't take a hint, and, most of all, they don't want to spread knowledge. They just want a free stamp of approval & marketing tool (see, Linus or whoever endorsed us by including our code, and a "wink, wink" with an elbow nudge) for their proprietary product. Fortunately, we already have Xen with which we don't have to observe politics of single company being discriminatory to prospective customers and ignorant of existing ones. On the paying side we have VMware, which doens't play politics, but just trying hard to create best products possible. Well, thank you very much SW-Soft, but reform, or take your crap somewhere else. I neither want, nor like code from hipocrytes in my vanilla kernel. If you don't have & show ethics and professionalism towards paying customers, then you probably don't have ethics/professionalism at all.

Oh, and if somebody from SW-Soft would like to prove me wrong, my telephone number, fax & e-mail are all in your marketing department in HQ. If you don't know which are mine (i.e. you have more than one such prospective customer ignored), then you have a bit more of a problem than you think.

Re:Anyone worried?

[Tony Hoyle]

It is... Virtuozzo is junk - my last host forced everyone to transfer to it (from UML, which was working fine for over a year).

Despite doubling the amount of available memory to everyone as a sweetner* it ran like a dog.. it was *really* slow - about half the speed of the UML solution. Sure it was pretty, but it spent most of its time spitting out 'out of resources' errors, and would randomly terminate applications - quite often the ssh server, meaning you had to keep rebooting... After 24 hours of almost solid downtime I (and a great many others with the same host) switched providers. I picked one that used Xen - which has been running sweetly ever since).

We don't *need* OpenVZ. Xen is much better already.

(* A sweetner not just because Virtuozzo was a resource hog, but because it couldn't do the same bandwidth management (previously we were on a 20mb link with 150gb/month.. vz had no way of doing that so they dropped us to a 512kb link - slower than my DSL line..)

Re:Anyone worried?

[Anonymous Coward]

What you say is pure speculation and really subjective. It was probably caused by a fact that Virtuozzo allows much higher VPS density than UML, and you provider just put too many VPSs on a single server. Such problem is not a problem in software, it is a problem with that HSP.

If you want to claim something is better/worse/faster/slower/rules/sucks, it should be backed up with results of some tests done in lab -- otherwise it's nonsense.

Re:Anyone worried?

[Anonymous Coward]

How can OpenVZ, or not-for-free Virtuozzo, for that matter, be worse than free VServer, if most people are using Virtuozzo? Are they morons?

No, they are not. They use stuff that works. Virtuozzo works, VServer doesn't.

Re:Anyone worried?

[Jenty]

Could you please describe what you mean by "resource hog"? Like when you run 200 VPSs, each with network applications and databases? :-)

And BTW, HSPcomplete and userland tools have nothing to do with OpenVZ inclusion into Linux kernel - that's another story.

Re:Anyone worried?

[greenrd]

you provider just put too many VPSs on a single server.

That doesn't sound likely, since the GP stated the memory allocated was doubled. Or perhaps you are saying that Virtuozzo is not designed to support as many concurrent VPSs as UML on the same machine?

That would mean Virtuozzo is very poor, because UML is a major resource hog, and is not designed to be particularly efficient. In theory, partitioning software should be the most efficient possible way to create "virtual root jails".

Re:Anyone worried?

[ovz_kir]

Or perhaps you are saying that Virtuozzo is not designed to support as many concurrent VPSs as UML on the same machine?

Virtuozzo/OpenVZ is designed to support hundreds and thousands VPSs on the same machine. I'm not sure about UML (it was limited to 40 instances per box a few years ago, due to a limit of tun/tap devices in kernel), but we are able to run hunrdeds and thousands of VPSs on a decent hardware. Say, a box with 4Gb of RAM can easily accomodate about 800 Virtuozzo VPSs (with no or little swapping) -- and I personally done that and seen that, it is not like "somebody said something". With more RAM comes more VPSs - they scale up in a linear fashion.

And yes, Virtuozzo *is* designed to be very efficient and lean on hardware. In SWsoft QA labs they do a lot of performance and scalability testing, making sure Virtuozzo gives the best it can.

Finally, what is the reason why people spend money for Virtuozzo, if they can have UML for free? Perhaps it works better for them?

That's the beauty of OSS

[TheAxeMaster]

If you want something in there, then by god, put it in there. There's no huge patchwork system that affects everyone using linux when one company wants to change the underlying functioning. They can do it, and sell it if they can, while the rest of us can go happily on our way not using it.

Re:That's the beauty of OSS

[mendaliv]

Exactly- if it gets into the kernel, it's not like it would default to include itself in the kernel build.

It'll more than likely end up as one of those "If you don't know what this is, you don't need it" features.

Memory is like an...

[Slipgrid]

Memory is like an orgasm. It's a lot better if you don't have to fake it. --Cray Seymore

Re:Memory is like an...

[slavemowgli]

"Cray Seymore"? The guy's actually called "Seymour Cray", y'know - you managed to switch his first and last name around *and* add a mistake. :)

Re:Memory is like an...

[Anonymous Coward]

Gee, he missed a comma. Is this still Slashdot? Let me mod you insightful. Cray, Seymour!

Re:Memory is like an...

[Dr. Evil]

He didn't miss a comma, he just faked it.

Re:Memory is like an...

[Anonymous Coward]

More than a few cases of Alzheimer's around here then, I reckon.

Hardware support?

[Visaris]

Both Intel and AMD are releasing CPUs which support OS partitioning in hardware this year (2006). Does the OpenVZ project support or have plans to support these hardware features?

Re:Hardware support?

[Anonymous Coward]

Zero Overhead....A Xen implementation will never beat a Vserver type implementation.

Re:Hardware support?

[LurkerXXX]

Along those lines, I've read a bit about this, but I've never read exactly what it is that this will do, just that 'it helps with virtualization'. I run VMWare now. Will this new hardware support do anything for me, or will it just make it easier for the VMWare folks to write their program?

Re:Hardware support?

[Anonymous Coward]

It might very well speed up the performance of VMWare, while making it easier for the VMWare folks as well. But from an OSS point-of-view, it should allow Xen 3.0 to boot unmodified kernels (Linux, FreeBSD, NTOS or other) and elminiate the need for VMWare.

Re:Hardware support?

[Wesley Felter]

OpenVZ won't benefit from virtualization-assist hardware features.

Re:Hardware support?

[SirTalon42]

Xen vs Vserver makes no sense. Vserver isn't meant for running multiple, unrelated, operating systems.

Re:Hardware support?

[htd2]

Xen and Vserver don't really compete except at a 30,000 foot level.

Xen allows you to host a number of different kernels and if you want different OS's on the same platform, it does this by providing a hypervisor that allows multiple OS's to run on the same platform at the same time. In theory at least the OS instances hosted by Xen do not need to be Xen aware.

Vserver impliments something akin to BSD Jails or Solaris Zones hosted on a single kernel.

They both have their advantages and uses.

Xen supports multiple copies of the same OS at different patch levels and versions as well as hosting entirely different OS's on the same platform at the same time. This can be an advantage and a disadvantage. From a development perspective being able to support a number of different revisions of the same OS on the same platform at the same time can be attractive, from a production perspective this can be less so.

From an efficiency perspective Vserver should win over Xen every time as would Solaris Zones and BSD Jails.

From an availability perspective Xen should provide higher levels of availability than Vserver because a kernel crash in one partition should not cause a crash in another and at the same time Xen should allow a hardware failure for example a CPU failure to be isolated to the partition(s) being hosted by that CPU. Of course you could argue that you are simply swapping a single point of failure at the Linux kernel level hosting Vserver for a single point of failure in the Xen hypervisor.

It should also be pointed out that comparing Xen hosting Linux with Solaris Zones from an availability perspective is less advantageous from to Xen because Solaris can survive the failure of a CPU provided it isn't running the kernel.

IP Rights secure on this?

[blastard]

Has there been a serious investigation of potential patent claims against OpenVZ. This looks like a potentially hazardous inclusion.

If due diligence has been done, and no problems on the horizon, then that's great. Just would hate to have something like this included and have it open up another SCO-like situation. Recognizing that one is Copyright based, and the other would probably be Patent, and in particular US patent based.

Re:IP Rights secure on this?

[WhiteWolf666]

License it under GPLv3 :)

Re:IP Rights secure on this?

[Nimey]

Dude, questions end with a "?", not a ".". It just looks bad and is bad English.

Re:IP Rights secure on this?

[jonabbey]

You're right, it would seem that this would be the sort of thing that the software patenters would have been all over, but you can't patent something if there's prior art, and there was a lot of prior art in virtualization way before software patents were ever granted in this country.

If things like VServer and OpenVZ violate patents, I'd expect that the FreeBSD 5 Jail system would as well, and I've not heard of any patent action against the FreeBSD folks on this ground.

Re:IP Rights secure on this?

[Jesus_666]

Do you really think so. Does substituting a period for a question mark make the poster look stupid.

Re:IP Rights secure on this?

[Hal_Porter]

We should have a "-1 GRAMMER NOOB!11!" mod category.

I can understand one thing

[oztiks]

If they want to have aspects of OpenVZ added to the kernel to support the lower level functionality like they do for UML and XEN then really this artical isnt anything really worth talking about it just seems normal and i wouldnt see Tovalds knocking back such a request.

If its anything more then that then yeah, they'll get told to bugger off (and so they should).

BTW i didnt RTFA on this one :)

Xen

[chabotc]

Wasn't redhat doing a major Xen push too? Fedora Core 5 will include xen host and guest kernels plus xen3, and from what i heard their putting a major effort into getting that usable too.

Never bet on a single horse i guess?

Or am i missing something and are OpenVZ and Xen very different products? (doesn't sound like it)

Upside of Xen seems to be the ability to run *bsd and other OS's in guest domains too, no mention of this in OpenVZ

Re:Xen

[adamshelley]

From: the website

Second technique: Para-Virtualized Machines. This technique also requires a VMM, but most of its work is performed in the Guest OS code, which in turn is modified to support this VMM and avoid unnecessary use of privileged instructions. The paravirtualization technique also enables running different OSs on a single server, but requires them to be ported. The paravirtualization approach is used by Xen, UML.

Third technique: Virtualization on the OS Level. Most applications running on a server can easily share a machine with others, if they could be isolated and secured. Further, in most situations, different operating systems are not required on the same server, merely multiple instances of a single Operating System. OS Virtualization systems have been designed to provide the required isolation and security to run multiple applications or copies of the same (or similar i.e different Linuxes) OS on the same server. OpenVZ, Linux VServer are examples of OS virtualization.

Re:Xen

[sakielnorn]

Or am i missing something and are OpenVZ and Xen very different products? (doesn't sound like it) Upside of Xen seems to be the ability to run *bsd and other OS's in guest domains too, no mention of this in OpenVZ

Essentially, Xen creates a new kernel for each virtual machine instance (or dom-u), while OpenVZ appears to use the same kernel instance for each virtual server. The latter approach seems to have benefits for performance and scalability, but if you discover a kernel bug in an OpenVZ server, all other instances are immediately susceptible, whereas with Xen, only the dom-u you are in is exploited (though if all instances are running the same kernel, you're up the creek). You'd generally need to be able to exploit the dom0 in order to affect all dom-u's.

Obviously, you're right about Xen supporting multiple OSes per instantiation versus OpenVZ.

Re:Xen

[Otter]

but if you discover a kernel bug in an OpenVZ server, all other instances are immediately susceptible, whereas with Xen, only the dom-u you are in is exploited (though if all instances are running the same kernel, you're up the creek).

Does anyone actually run Xen with multiple kernel versions on productions systems? It seems like an enormous source of work and trouble with very minimal return. It's not like the vulnerabilities and bugs in 2.6.n weren't almost all in 2.6.n-1 as well.

Re:Xen

[DShard]

but what if you wanted to run redhat WS 3+4 and debian sarge. the kernels there are not even close to being the same. Of course at this point it would be a big pain to even think about that, but after hardware virtualization gets in place its a no brainer.

Re:Xen

[slamb]

Or am i missing something and are OpenVZ and Xen very different products? (doesn't sound like it)

They have similar goals, but they're pretty different technically. For example, with Xen you have to partition the memory space quite rigidly - each virtual machine gets 128MB or whatever. They can't borrow from others memory that's not being used. So if you look at a Xen-based virtualization provider like RimuHosting, you'll see that their highest virtualized configuration gives you 320MB of memory. If you look at a Virtuozzo-based one like JohnCompanies, you'll see the other extreme:

[slamb@scooby slamb]$ free
total used free shared buffers cached
Mem: 8275068 8206096 68972 0 1696704 1678948
-/+ buffers/cache: 4830444 3444624
Swap: 6144852 4097468 2047384

That's one of the most obvious differences. Another is that Virtuozzo's rather customized kernel tends to lag behind - my virtual server is a 2.4 release that annoyingly lacks NPTL. I imagine that's what they're trying to address with OpenVZ and mainstream kernel inclusion.

(Incidentally, both the hosting companies I linked to are nice places with open source developer discounts.)

Re:Xen

[nathanh]

Or am i missing something and are OpenVZ and Xen very different products? (doesn't sound like it)

Yes, they are very different things. OpenVZ is more like BSD Jails or Solaris Zones (aka Solaris Containers). Xen is more like mainframe virtualization and very roughly like VMware (though not as useful).

OpenVZ is probably faster because kernel resources are shared. Xen permits different kernels or even different operating systems to run at the same time. OpenVZ will scale to a larger number of simultaneous instances. Xen is more robust because a kernel crash in one instance won't affect another instance. OpenVZ is simpler. Xen is more flexible.

Re:Xen

[superpulpsicle]

I believe this is not the first time Linux can be splitted like a container. When Linux runs on IBM hardware, it can already split into Sysplex and LPARs.

Re:Xen

[JonAnderson]

That service is provided by the hypervisor and has nothing at all to do with linux.

Re:Xen

[devovz]

coming Virtuozzo 3.0 (based on OpenVZ) will have NPTLs.

That's Seymour Cray

[Anonymous Coward]

Of Cray supercomputer fame...

http://en.wikiquote.org/wiki/Seymore_Cray

(Note the redirect from Seymore to Seymour)

This is an idea I like

[THEUBERGEEK]

I have often wanted a means to run 2 OS instances on one machine. I, personally, would like a way to run FC5 and winXP simultaneously. This definately seems like a step in the right direction.

Re:This is an idea I like

[Anonymous Coward]

Xen is a step in the right direction, and with VT or Pacifica it is a reality.

Re:This is an idea I like

[Anonymous Coward]

I have often wanted a means to run 2 OS instances on one machine. I, personally, would like a way to run FC5 and winXP simultaneously.

Dude, that is so NOT what this is.

Re:This is an idea I like

[glowworm]

From wikipedia "Whereas VMs attempt to virtualize "a complete set of hardware," VPSs represent a "lighter" abstraction, virtualing instead "an operating system instance." All VPSs run atop a single operating system kernel. The VPS mechanism multiplexes this one OS kernel to look like multiple OS (and server) instances, especially from the perspective of running applications, users, and network services.

You don't want a VPS, what you want is something to create a VM like VMWare. It creates seperate virtual machines allowing you to run (like I do) Gentoo and XP at the same time.

Re:This is an idea I like

[aevans]

You don't want a VPS.... but your hosting provider does, especially now that off the shelf hardware is so fast that under full load, if you divide the CPU by 10 or even 100 under lighter loads, your'e still I/O and network bound.

Re:This is an idea I like

[BrookHarty]

But, paravirtualization is faster than Virtual machines. Xensource booted windowsxp, but I never saw a downloadable product. Performance wise, you could get a large speed boost and run both WinXP and linux. If its true and OSX and XP Both are have xen packages, that will be some very interesting configurations this year.

Re:This is an idea I like

[SirTalon42]

You aren't gonna be able to download a Xen image of Windows because that would be copyright infringement. The original version of windows running under xen was made when Microsoft was still working with the Xen devs.

Re:This is an idea I like

[Anonymous Coward]

With the new Vanderpool/Pacifica stuff in this year's chips, you're supposed to be able to run operating systems on Xen without the modifications they used to need.

Re:This is an idea I like

[Just Some Guy]

You don't want a VPS

Yes you do - you just don't know it yet.

I've been using FreeBSD jails (similar idea) for a few years, and that kind of virtualization is a great way to isolate potential security exploits from the rest of the system. Want to try a binary-only application? Fire it up inside a jail. Need to run some PHP app with a sketchy track record? Host it on a jailed Apache server.

Many of us are starting to use jails where we would have used chroot a few years ago. I know I'm hopelessly geeky, but my desktop machine is running three full-fledged jail systems - that is, complete images that I can SSH into and play around inside of - as I write this. When you can do such things with almost zero runtime overhead, there's no great reason why not to.

Perspective

[kbahey]

SWSoft are the makers of Virtuozzo a commercial product that allows hosting companies to offer Virtual Private Servers.

A rival technology is Xen from Cambridge University, which is free.

Galaxy

[msbsod]

Nice to see some progress in the Linux arena. But neither the quoted article nor the OpenVZ web site list too many alternative solutions. Here is one from another world (non-unix): OpenVMS Galaxy by Digital (now HP). Galaxy is part of OpenVMS, since more than half a decade.

http://h71000.www7.hp.com/wizard/wiz_3191.html (check the date - 1999!)
http://www.s-and-b.ru/syshlp/vms_html/6512/6512pro .html (an early online documentation, hosted by on a non-Digital/HP system)
http://h71000.www7.hp.com/availability/index.html (Lots of information about High Availability/Disaster Tolerance)

"All the world's a stage" or was it "All the galaxy's a stage?"
http://scifi.about.com/library/weekly/aa022800b.ht m

Re:Galaxy

[Anonymous Coward]

Nice to see some progress in the Linux arena

err... XEN?

Actually, I know you're just carma-whoring so whatever.

Re:Galaxy

[oldmanmtn]

Here's an even more direct comparison: http://opensolaris.org/os/community/brandz/

This lets you run multiple Linux instances on top of Solaris.

Re:Galaxy

[neurojab]

Half a decade? Bah.
OS virtualization has been in common use since
1968!

Re:Galaxy

[perthling]

IMHO, the really different and useful thing about Galaxies are that they are usually composed of clustered virtual machines. And OpenVMS clusters are really, really useful and seamless.

Running Windows XP and Linux simultaneously

[RidiculousPie]

There are several ways to do this, with varying levels of stability and performance.

QEMU will run Linux, BSDs, and Windows, from either Windows or Linux.
Colinux will run linux from Windows XP. I'm not sure what the latest Fedora Image for it is, but I run a 2.6 kernel based Gentoo build from XP frequently (for that nethack fix).

I'm not sure either is suitable, but i would recommend looking at them, as they are both interesting projects, if not immediately useful to you.

Re:Running Windows XP and Linux simultaneously

[Forbman]

CoLinux is pretty swank from within Windows.

You don't like nethack on Win32? That's how I get my nethack fix.

The only problems I have are getting networking to work right between the colinux environment and Windows. The instructions for it online in the colinux wiki suck.

User Space Linux?

[molo]

How does this benefit over current inclusion of User Space Linux? Does it allow other operating systems a la VMware? Is it platform-agnostic? Any info?

-molo

Re:User Space Linux?

[ovz_kir]

There are three different types of virtualization, they are outlined in this short article.

In short, OpenVZ uses the single-kernel virtualization approach, which differs from either VMware or Xen: instead of trying to emulate something, kernel is modified to support multiple isolated environments, so each such environment looks-and-feels like a separate server. Good things about it is (1) best possible performance (no to little performance overhead due) and (2) hardware resources (CPU, RAM etc.) are controlled from within a single kernel, so resources are used most effectively.

Pros and cons

[countach]

So what are the pros and cons of Xen versus OpenVZ? My initial reaction is that Xen is the way to go because it is REALLY running different Linux instances. This is good because you can upgrade different instances to different OS versions. I know on those big Sun boxes with virtual environments its a pain in the butt because to upgrade the OS you have to upgrade a zillion applications at once to the new OS version which is a nightmare. But with real virtualisation with completely different kernels running you can upgrade one virtual instance to a completely different kernel without affecting hundreds of other apps running on the same machine.

Re:Pros and cons

[Anonymous Coward]

They aren't quite the same thing. Xen is more useful in a number of situations, but requires multiple copies of the kernel to be running. Yes, in some instances it is an advantage (such as when developing kernel drivers, so that a panic/oops doesn't take down the entire system), but for hosting (which is what Virtuozzo is for), you want better resource usage. Unfortunately, OpenVZ doesn't include the filesystem driver, which gives much better resource sharing, but at least it still includes the per-VPS resource limits (called ubc in OpenVZ).

With OpenVZ or vservers, a user could (in theory, I've never heard of it actually happening) take a remote user exploit, then if there is a local kernel exploit they could take control of (or at least crash) the entire machine. With Xen, it isn't possible for a VPS user to take control of the entire machine, even if there is a kernel exploit for the VPS kernel.

The bottom line is that, right now, OpenVZ provides a lot less isolation and a little more resource sharing than Xen, and a lot less resource sharing but a little more resource control than vservers. If XenFS is finished, then OpenVZ will provide a lot less isolation and a lot less resource sharing than Xen...

Something else to know about Xen is that although 2.x let you assign devices to a guest kernel, Xen 3.x does not allow that yet. That means you can't yet develop hardware drivers in Xen 3 guests (like you could under Xen 2.x) and you can't do things like run a MythTV backend or hardware accelerated graphics in Xen 3.x. Of course, OpenVZ can't do any of that anyway, but that's a really handy feature of Xen 2.x, and it is expected to eventually return to Xen 3.x.

Re:Pros and cons

[Anonymous Coward]

but if OpenVZ is based on a single kernel running, and all processes are 'isolated' from each other, via kernel process separation, then you can easily run hardware drivers in OpenVZ. All you have to do is install them normally and every process gets to use them. Otherwise OpenVZ would be a bit useless if none of the user processes could interact with the kernel.

Xen, on the other hand, does require modified drivers as it runs multiple kernels to achieve its process separation, and they'd have to play nice with the hardware that another running kernel is concurrently using.

Re:Pros and cons

[Anonymous Coward]

At first I couldn't even figure out what you were referring to, but I understand you are talking about the MythTV isolation and such. Xen does NOT require custom drivers to allow guests to talk to hardware under 2.x (and soon under 3.x), but rather it only allows one vm to talk to hardware that doesn't have a custom driver. In this case, that's what we'd prefer. Only one vm could sensibly talk to a video capture device (what would be the point of multiple ones?) but with Xen you can ensure that even a driver bug will not take down the whole system, just the one VM that is directly accessing that card. Xen can even restart the VM automatically. Under OpenVZ, the entire system would crash in that case.

As an example use case, (that has actually been documented as is currently in use) you might have one system that is handling your local web server, mysql server, mythtv backend, network firewall, and astrisk pbx. If the Myth backend crashes (as it sometimes does) you don't lose telephone service! That's a good thing. Usually the problem is with Myth itself, not the kernel driver, but by using Xen we can be safe even if the video capture driver (or something else in the kernel used specifically by the myth backend) crashes. OpenVZ can't do this, because it doesn't isolate the kernel used for different tasks.

Re:Pros and cons

[Anonym0us Cow Herd]

It would be helpful if there were a chart comparing pros and cons of various virtualization approaches.

In particular, Xan has an advantage that different operating systems can run concurrently.

If you want Linux, and only Linux, then OpenVZ/Vserver might be a better solution. But if the single kernel crashes, all of the isolated virtualized sets of processes also crash. Under Xen, if one kernel crashed, the other kernel's (which might even be a different OS) are less likely to be affected.

OpenVZ/Vserver might make more efficient use of memory. This is an assumption. A single kernel is managing memory. Memory unused by one isolated group of server processes might be used by a more heavily loaded group of server processes on that same kernel. With Xen, you pre-allocate a fixed amount of memory to each domain, and the OS that boots into that domain has that much memory, even if it is not being efficiently used.

VMWare seems to me to be most like Xen in the pros/cons department, except for the emulation inefficiency. Xen requires an OS to have minor alterations to port the OS to run on Xen (paravirtualization), while VMWare can run any OS unmodified (or that you are unable to modify *cough* Windows *cough*).

In 2006 once Intel/AMD have virtualization in hardware, and once Xen supports it, then the one advantage that VMWare has (run unmodified Windows OS) will disappear, as Xen will also be able to do this.

Have I missed anything? Are there other pros/cons I have overlooked?

Re:Pros and cons

[Just Some Guy]

My initial reaction is that Xen is the way to go because it is REALLY running different Linux instances.

It depends on what you're trying to accomplish. If you want to host full-blown virtual machines, each with their own static resources, then Xen is great.

If you're only trying to isolate one specific application, though, and you're not sure how much memory, disk, or CPU to allocate to it, then the style of virtualization that OpenVZ (among others) uses may be exactly what you needed.

Re:Pros and cons

[sgt scrub]

You didn't mention the differences in communication between VPS's.

OpenVZ and FreeVPS can move traffic via Tun/Tap/Bridge interfaces. You are able to forward network traffic from one Vserver to the other without it going over the hardware interface. eg. traffic can enter the hardware interface then get PAT/NAT'd over a bridge to a specific machine. That machine can in turn do the same. Vserver and VMWare can only share the hardware interface. I'm not sure about Xen. But, I will be finding out soon.

Anyone know why FreeVPS is still using Redhat 7.3 instead of 9?

Re:Pros and cons

[ovz_kir]

If XenFS is finished, then OpenVZ will provide a lot less isolation and a lot less resource sharing than Xen...

This is not just XenFS. The good thing about single kernel approach is there is a single place from which you control all the hardware resources. With Xen, it is hard (almost impossible) to change the amount of memory given to the guest, without restarting it. More to say, _all_ the memory you allocate for the Xen instance will be taken once you start it, whether it is actually used or not. So, you (1) waste memory, (2) can not reallocate it dynamically. This leads to worse scalability, i.e. you can not run as many Xen instances as you would do with OpenVZ.

And yes indeed, with OpenVZ you have both limits and guarantees for the resources such as memory. So, an OpenVZ instance (a VPS, a guest) is guaranteed (unless you overcommit the resources) to have not less than X megabytes of RAM, and is limited to Y megabytes of RAM. Because of that, you can have more instances running -- tests show that about 100 VPS can run happilly (with no to little swapping) on a box having 1GB RAM.

Re:Pros and cons

[jonabbey]

Xen uses Bridge interfaces in the Dom0 operating system host.

Re:Pros and cons

[Anonymous Coward]

I realize that nobody is probably still reading this article, but for the sake of posterity...

Yes, with XenFS, Xen would would share resources much better, even with what you are saying. That's because without vzfs, openvz can't share application or library memory efficiently. The result is that you can't actually USE 100 ves with 1 GB of ram. Once you start loading apache+php+mysql+sendmail+proftpd+xinetd and running things (so they don't swap out), openvz will stop working for you.

Of course, this is just what I've been told. I've been told it is why people need to upgrade to virtuozzo. I suppose you could try bind mounting things in from other locations, or hard linking, but this doesn't prevent those files from being overwritten across VEs and other trouble.

As for re-allocating memory, yes, Xen can use the balloon driver to re-allocate memory on the fly. I do it all the time. You boot up with Y MB Ram and then balloon down to X MB (in your example). The only improvement would be if the oom killer would try to reallocate via the balloon driver if it needed to. Normally though you can make some swap space to take care of that problem.

Speaking of memory allocation, under openvz/virtuozzo, it is possible to cause the system to mmap much larger areas into memory than the memory limits allow. I read on the openvz mailing list (or maybe forums, in any case the message was from an swsoft employee) that this problem exists in both vservers and openvz. I won't detail exactly how you do it, but I did verify that it works. That's one of the many things (eg guest kernel panics) that aren't an issue with Xen.

Re:Pros and cons

[ovz_kir]

The result is that you can't actually USE 100 ves with 1 GB of ram.

I was actually able to run 200 VPSs on the same 1 GB of RAM, but the swap was horrible and the apache performance was very low -- but it worked! In case with 100 VPSs each running apache, sendmail, xinetd and sshd -- there was little to no swapping, and apache performance (serving a few 10Kb static pages) under high apache load was just fine.

So when I say "100 VPSs" it is indeed 100 VPSs - no tricks, no cheating, and you can try it yourself. Ask for more configuration details if needed.

Definitely, if you use MySQL and some other stuff like that, you can end up with as low as 1 VPS -- that basically depends on MySQL configuration and server (VPS) load.

Speaking of memory allocation, under openvz/virtuozzo, it is possible to cause the system to mmap much larger areas into memory than the memory limits allow. I read on the openvz mailing list (or maybe forums, in any case the message was from an swsoft employee) that this problem exists in both vservers and openvz. I won't detail exactly how you do it, but I did verify that it works.

Currently we know of no such exploits in OpenVZ or Virtuozzo -- so can you be more specific here and provide some info or URLs to those posts?

Sure we do understand that kernel is a critical piece in such a technique as used by OpenVZ -- and we do care about our kernel quality. This is the reason OpenVZ is still based on 2.6.8 -- for the same reasons RHEL4 is still based on 2.6.9 kernel -- stability. Actually, the fair share of OpenVZ patch is just bug fixes and driver updates, not virtualization. And we do *a lot* of quality testing in house -- to make sure kernel is stable and solid as a rock, and it is very stable. Feel free to prove otherwise -- we will be happy to hear about bugs or security holes in OpenVZ.

Virtuozzo and OpenVZ

[gantry]

Although Virtuozzo is "built on top of OpenVZ", is Virtuozzo's kernel component a publicly available version of OpenVZ, built without using any proprietary patches or modules?

http://openvz.org/documentation/tech/virtuozzo states "Differently from OpenVZ, Virtuozzo(TM) is developed and designed to run production workloads in 24×7 environments ..."

and goes on to list, among Virtuozzo's advantages over OpenVZ:

"Higher VPS density. Virtuozzo(TM) provides efficient memory and file sharing mechanisms enabling higher VPS density and better performance of VPSs.

"Improved Stability, Scalability, and Performance. Virtuozzo(TM) is designed to run 24×7 environments with production workloads on hosts with up-to 32 CPUs."

Why should Linux accept a kernel patch if (unlike Linux itself) it is not designed to run 24×7 environments with production workloads on hosts with up-to 32 CPUs?

Re:Virtuozzo and OpenVZ

[devovz]

Virtuozzo is not just about a kernel patch, it's a set of management tools built upon OpenVZ infrastructure. It's more tested/better supported (for money) etc. This is why in general its quality is better. Exactly like with Fedora/RHEL, which one would you use in production?

Re:Virtuozzo and OpenVZ

[demon]

Based on some of the comments from people who've *used* the commercial product, it sounds like there might be some disagreement on this point...

this has nothing on Solaris Zones

[Anonymous Coward]

well this will probably run multiple kernels, but probably means multiple times the work and the administration headaches, with Solaris Zones you share the kernel, but you only need to administer one core install of the OS.
 
A base install of Solaris in a zone, uses just 100MB of harddisk space. And on modern hardware takes less than 15 minutes per zone to install. Of course if you use the latest and greatest Solaris Express releases, you can use ZFS+Zones to cut the size of each zone down to 50MB of disk space, and zone creation time down to create a zone in 1 minute or less. You could also download and install brandz(Solaris patches that allows user to run Linux binaries in a Solaris Zone), and have even more choice. If you wish to debug your apps, you can use a stable dtrace and debug userland of both Solaris and Linux. And the Solaris kernel.

Re:this has nothing on Solaris Zones

[demon]

It doesn't run multiple kernels. It's like a FreeBSD jail() on steroids - has a virtual local network stack and process space, but everything is still running under a common shared kernel. IMO Xen is still far better (and many people agree with me, it seems).

As far as Solaris Zone setup time, I have my own scripts that already set up a new Xen domain in a matter of a couple minutes from scratch for several Linux distributions - Sun's hardly doing anything earth-shaking there...

Arg!

[Stumbles]

Hmmm, that smell. That smelly smell that smells..... like..... we demand that we are not demanding you do as we demand cause we got clout on our side. Hrmphf.

Re:Top seller

[Anonymous Coward]

Because Red Hat is defending your first amendment right to free beer!

Pfft

[drix]

Real men use
# chroot /var/secure /vmlinux

No worries about companies, just about quality...

[Anonymous Coward]

I've got to agree with the parent that there's no reason to fear companies putting software into the kernel. Lots of them do, and we're always encouraging companies to write open source drivers in the kernel.

What follows is purely speculation based on my feelings. Do not consider it to be factual, or make stock/software purchasing or sales decisions based on it. YMMV, IANAL, whatever.

The real problem I see, as an ex-swsoft customer, is that they really don't care as much about bugs or broken features as they do about marketing points. They made all sorts of claims about their software when they sold it to us, but many things weren't ready for nearly a year by which time we were forced to pay an additional "maintenance" fee if we really wanted to get those features. (or for that matter, any security updates) By then we were so dissatisfied with Virtuozzo and HSPC, we didn't bother paying for the upgrade. They also refused our requests for access to their source RPMs, even ones marked as being GPLed.

I've looked over their OpenVZ information already, to see if they are finally playing nice with the open source community, and the first thing I noticed is that they are refusing to release vzfs, which is required to get any decent performance/scalability with Virtuozzo. They're doing it for marketing reasons, i.e. they want people to view OpenVZ as something of a demo product before getting the "real" product, Virtuozzo. I believe they could easily release vzfs if they wanted to, but they recognize that their customer support (and programming quality) is such that nobody would willingly pay for it if they could get the software source code for free. Also, they'd probably quickly be cut out of development, because their code lacks the quality of that normally found in the linux kernel, and there are plenty of other people (eg vservers) who would take over.

If anyone really wants to get full Virtuozzo style resource sharing into linux, I suggest they start working on either XenFS or some vservers based copy-on-write filesystem. Without vzfs, OpenVZ is barely an improvement over vservers in that it supports "user beancounters", and it is barely an improvement over Xen in that it supports a shared kernel resources. If XenFS was functional, Xen would be a much superior product in terms of resource usage and security, at the very slight cost of an extra context switch for guest/host inter-kernel communications. If vservers had something equivalent to the UBC code, then (thanks to vservers unification) it would have all the functionality of Virtuozzo. The only thing missing in either case is commercial support, and I'm sure there would be people happy to offer that as well.

On the other hand, I'd be happy if they did release vzfs, not because I plan to use it, but because I think more choice is better. I'm not sure I'd want it in the kernel over Xen or vservers though.

non-graphical interface?

[egburr]

What I'd really like to know is if there will be some way for me to ssh in to my server and "press" the power button for a virtual machine and have it start up. Or, will it require that I be able to export my display before I can start it up? And would there be any way to remotely grab the console of an already active virtual machine?

Re:non-graphical interface?

[aspeer]

I think you are hinting at the requirement of VMWare Workstation and Player to "need" a display before they will run a VM.

You can work around this requirement using the X Virtual Frame Buffer (Xvfb). Install Xvfb and the associated xvfb-run script (google it if it is not part of your distro - it comes with Debian but can be downloaded separately).

Then run vmplayer/workstation thus:

xvfb-run /usr/bin/vmplayer /data/vmware/wxp-cv/winXPPro.vmx

Your VM will start in a virtual display, and run for as long as that display does. If you use VNC or similar you should be able to connect to both the virtual display and the VM session (theoretically - I have not tried that part of it).

Re:non-graphical interface?

[Anonymous Coward]

Your question doesn't quite make sense under OpenVZ. There isn't a console per se in OpenVZ guests, just as there isn't a separate kernel. You certainly can enable/disable guests at runtime via the command line, and they run through the boot process, but they don't have their own kernel or console. Once you do "vzctl start 1234" the system will run init within VPS number 1234, and then "vzctl exec 1234 some regular command" can be used to run a command within VPS number 1234, or "vzctl enter 1234" will give you an interactive shell (/bin/sh) executed within VPS number 1234. It isn't the same as a console though.

If you were running Xen, you'd get a real console when you did "xm console vm1234" (after creating the vm). But that's because it is running a real, complete linux kernel within the VM. It still wouldn't require you to export your display or anything like that, it's just a text console. I believe Xen 3.x also can export a VNC (graphical) display if you've got a VT enabled processor/BIOS (the new Macs supposedly have the processor support, but it is disabled), so that you can run Windows XP or whatever, and that runs without any modification to the guest OS at all.

Re:non-graphical interface?

[sgt scrub]

You can remotely stop the servers just as you would any other Linux system (poweroff, halt, shutdown -h now). You can remotely start the servers by loging on to the base/host OS and running a start script (Vserver and OpenVPS). You can have multiple X Window System servers (one on each vserver including the base/host OS). You can ssh -X or XDMCP to remotely use GUI interfaces to any of the X Window System servers.

Re:non-graphical interface?

[ovz_kir]

I used to run X Window inside an OpenVZ VPS (based on Fedora Core 4) and access it via VNC from my desktop. Runs perfectly fine, even xscreensaver is working :)

OpenVZ/VServer versus hardware virutalization

[jonabbey]

OpenVZ doesn't care about processor virtualization features. OpenVZ (like VServer) is all about implementing a system like FreeBSD jails. In this model, there's only one kernel running, but different sets of processes are isolated from each other through operating system features. The separation applies to things like the 'ps' command and the /proc interface in general, as well as things like sockets and networking.

With OpenVZ/VServer, you can set up security and network separation so that certain processes will think of themselves as on 'internal-web-server', while others will think of themselves as 'external-web-server', and the two sets of processes would not be able to interact with each other in ways other than through the same kind of networking connections that they would use if they were on separate pieces of physical hardware.

Something like Xen or VMWare achieves this virtualization by simulating separate processors, memory, and I/O space hardware. OpenVZ/VServer doesn't incur this overhead, but does require much more significant modifications to the Linux kernel, as lots of system calls have to be modified to enforce the process group separation rules.

Re:OpenVZ/VServer versus hardware virutalization

[stedo]

Something like Xen or VMWare achieves this virtualization by simulating separate processors, memory, and I/O space hardware.

Erm, no. VMWare does this, but Xen doesn't.

The whole point of Xen was to get rid of the overhead involved in simulating a real processor. Instead, the Linux kernel was ported to Xen, almost as if it were a new chip architecture. Something like VMWare has to check for the kernel trying to manipulate I/O or do paging, and translate those instructions into what VMWare wants them to do. Since Linux is open-source, there is an alternative.

When you are running a Xen kernel, all of the I/O calls replaced in the source code with Xen "hypercalls" which just send a message to the Xen "hypervisor" do check permissions and actually perform the action

Re:OpenVZ/VServer versus hardware virutalization

[jonabbey]

Yes, of course. If you read what I said, though, I didn't contradict that.

Just because Xen doesn't simulate a x86 processor doesn't mean that it doesn't simulate a processor. The processor that Xen simulates is a Xen-x86 processor, in which the only processor functions that have to be emulated are ones that are not virtualizable without Intel and AMD's upcoming virtualization ISA modifications, "Intel Virtualization Technology/Vanderpool", and "Pacifica".

But the kernel does boot and exceute on top of a processor environment provided by Xen, and that's the vital distinction I was meaning to draw in the comparison with OpenVZ and VServer.

Similar to...?

[ivoras]

Is this similar to FreeBSD jails http://www.freebsddiary.org/jail.php and Solaris Zones http://www.sun.com/bigadmin/content/zones/ or is it something new?

If it is, it's a good thing to have, though all that "commercial firm pitching a free version of their product into baseline kernel" thing sounds a bit dodgy.

you can...

[Anonymous Coward]

...go to their ftp servers and download all their packages for free, in source code if that's your prefs. If you want their latest bleeding edge stuff for funzies, go get Fedora. If you want their enterprise stuff all compiled into a nice ISO image so you can just burn it and run it, without doing any work yourself, just grab the latest CentOS image, or send off any number of places and get the physical disks for cheap, cost of duplication and mailing basically.. If that ain't free enough, well....

Re:Top seller

[Anonymous Coward]

Then you should probably try to avoid trying to figure out why people spend so much money buying things on the FREE market. Your head might explode.

Pund-IT?

[Mike Markley]

A Pund company name... awesome.

*waits for it*

Multiple Distributions?

[Anonymous Coward]

So can I run, say, SUSE, Gentoo and Mandriva?

Three Reasons...

[Anonymous Coward]

Here are the three possible reasons they're doing it, in order of likelihood:

1. They're attempting to sink a sub patent.
Solution: Build a non-commercially tied variant and put that in the kernel, too.

2. They're attempting to use the kernel developers as unpaid support staff. "Doesn't matter which distribution you have, it's supported by all of them." Later: "It's in the kernel, so it's the kernel developer's problem that it won't compile, not ours."
Solution: Duh, anyone can apply it as a kernel patch.

3. They're attempting to preempt their competitors by making it the defacto standard.
Solution: None needed. Anyone can apply it as a kernel patch.

Sorry if I'm cynical, it could just be a happy, pro-OSS company that wants to give away the store - and everyone there is just so happy all the time while they prance about and cuddle fuzzy bunnies and puppies and sing songs. ... Please don't accuse me of being ungrateful. If they want to give it, they can post it as a kernel patch and ask to have the source tree mirrored.

Re:Don't forget...

[Anonymous Coward]

4-month IP ban?

Re:Top seller

[paulius_g]

You do realize that when you buy Red Hat Enterprise, you're actually paying for technical support.

RHE is based on CentOS (http://www.centos.org/ It's also my favorite distro for both desktops and servers! So go try it out.

Great 1 more failed comedian turned marketing exec

[skiingyac]

Can I buy Pund-IT on eBay along with my regular "It"?

Seriously, when he's got some sort of reputation, does he expect people to introduce him as a "Pund-IT Analyst"? Lame

Zones, Jails

[Craig Ringer]

BSD Jails, and Solairis zones, are two well-tested options in this area.

xen is king

[MORTAR_COMBAT!]

xen has so much support, and soon in-hardware support from both AMD and Intel. xen is the virtualisation layer of now and the future.

Re:Top seller

[Burdell]

RHE is based on CentOS

You've got that backwards. CentOS takes the RHEL SRPMS released by Red Hat, rebuilds the binaries, and reassembles them into a distribution.

VPSes like OS/2?

[jbolden]

For anyone who has used this. Is the relationship like the way OS/2 (2.0-3.0) used to run Windows?

idea...

[luna69]

....Hey, let's just put EVERYTHING into the kernel! User space? Bah!

Xen ?

[d3matt]

Pardon my ignorance, but how is OpenVZ different from Xen? If there is little difference, why not just make a bigger push behind Xen rather than attempt to get their own IP into the kernel.

Re:Xen ?

[surprise_audit]

Xen runs a kernel per virtual machine instance, OpenVZ runs one kernel but maintains separate process spaces for each virtual system (or whatever they call it). So, with OpenVZ, *all* the virtual systems are running the same distro of Linux, but with Xen you can run several different distros (RedHat, SuSE, Debian, Mandrake), as well as a completely different OS such as NetBSD or FreeBSD.

Re:Xen ?

[JustNiz]

umm.. so Xen is better then, at least because it is more flexible.

Re:Xen ?

[ovz_kir]

With OpenVZ you *can* run different Linux distros - RHEL/CentOS, Fedora Core, SuSE, Debian, Gentoo - to name a few. The only common thing between different virtual environments is the kernel - OpenVZ kernel.

Re:Xen ?

[ovz_kir]

It is not quite like that. First of all, OpenVZ *is* able to run different distros in different virtual environments, as the *only* common part between those environments is the kernel -- OpenVZ kernel.

Second, Xen approach has its advantages and disadvantages. Among Xen advantages are, say, ability to run different kernels simultaneously, including non-linux (bsd) kernels as well, (theoretically) better isolation. But it comes with a price: greater virtualization overhead, lower resource utilization (thus lower density), inability to dynamically reallocate resources. Say, you can not run 100 Xen instances on a box with 1GB of RAM, but it's a trivial thing to do with OpenVZ.

Consider the third variant -- VMware. It gives you even more isolation and ability to run *any* OS, not modified at all. But again, as with Xen, it comes for a price: yet lower performance and density.

All the three approaches have their pros and cons -- and it's up to the user to decide which one suits his tasks and environment better.

The Linux devs should reject it's inclusion

[TheLink]

All the current x86 virtualization stuff is going to be out of date soon. It will be just adding kludges to the kernel to implement stuff that required by virtualization deficiencies in old x86 stuff. If you need those kludges, Xen should be enough.

This is because Intel and AMD are going to allow new and far more efficient ways of doing virtualization, with hardware assistance (lookup Intel Vanderpool and AMD Pacifica).

So, I don't see much long term gain for the effort for all the minuses.

You risk lower quality and increased maintenance costs. And you might also increase exposure to patent claims (but I bet IBM can smash anyone to pulp especially with virtualization patents).

You will still need developers to work on Vanderpool and Pacifica stuff, and I think you'd get better "bang for buck" with that (plus I think it will be a lot more fun).

Re:The Linux devs should reject it's inclusion

[trandism]

You risk lower quality and increased maintenance costs

Pardon me sir and nothing personal, but I don't give a SHIT about maintenance costs...
Since when do you people care so much about maintenance costs? That Raymond-dude really got into your brains didn't he?
If it's fun to use and doesn't break other things, put it in the god-damn kernel
And let the blood-sucking companies care or not about costs
Where's your hacker spirits for christ's sakes??

Re:The Linux devs should reject it's inclusion

[hughk]

The key work on virtualisation precedes IBM and it dates back to Cambridge University and Titan. Perhaps this is why IBM do not persue their patents on virtualisation much these days. IBM likes Xen and even has articles about it in their Developerworks website.

The Xen approach is more generalised than OpenVZ and they have already expressed their interest in supporting true VM supporting hardware like the AMD Pacifica. They also have the concept of being able to checkpoint and move VMs between machines. This is very interesting stuff. If anything was to go into the Kernel, I would prefer the Xen support.

Re:The Linux devs should reject it's inclusion

[Anonymous Coward]

It will cost kernel developers something to maintain it, that's what I meant. Note my post was totally from the perspective of kernel development - including the patent concerns[1]. I thought I wouldn't need to explain things to such detail, but I guess I was wrong.

If OpenVZ is written well then perhaps it will be easy to maintain. But as I mention - Why bother? They've already put in Xen, and the new x86 stuff will be out soon.

So what's so great about OpenVZ? What does it do that Xen doesn't already or won't be able to do soon?

[1] I wasn't that concerned about IBM's patent claims actually, I was just wondering if there are others with patents on the OpenVZ stuff.

Re:The Linux devs should reject it's inclusion

[devovz]

a lot of things... - OpenVZ allows to run 100 VPSs on 1GB RAM - OpenVZ has no Xen I/O overhead (20-40%) - OpenVZ natively supports SMP (and always supported) inside VPS (up to all of your CPUs) - OpenVZ starts/stops VPS in a few seconds - OpenVZ creates VPS in less than a minute - OpenVZ allows to change all VPS QoS parameters on the fly (disk space, CPU and memory limits) - OpenVZ allows much better resource utilization, it doesn't reserve VPS *unused* memory for future use etc. just from my mind... I can elaborate on this further.

Re:The Linux devs should reject it's inclusion

[ovz_kir]

So what's so great about OpenVZ? What does it do that Xen doesn't already or won't be able to do soon?

A lot of things actually, please consider a just a few:

• OpenVZ allows to run 100 VPSs on 1GB RAM
• OpenVZ has no Xen I/O overhead (20-40%)
• OpenVZ natively supports SMP (and always supported) inside VPS (up to all of your CPUs)
• OpenVZ starts/stops VPS in a few seconds
• OpenVZ creates a new VPS in less than a minute
• OpenVZ allows to change all VPS QoS parameters on the fly (disk space, CPU and memory limits)
• OpenVZ allows much better resource utilization, it doesn't reserve VPS *unused* memory for future use
• etc. just from the top of devovz's mind...

We can elaborate on this further.

Re:The Linux devs should reject it's inclusion

[Anonymous Coward]

devovz
ovz_kir

OpenVMz Droids! :)

Re:The Linux devs should reject it's inclusion

[ovz_kir]

Yes we are :) Nice to meet you ;)

VZ is not quite the same... but I agree.

[WoTG]

My virtual private server runs on VZ (which, I gather, is some sort of management suite that runs on top of OpenVZ). It works fine for me; however, I can see that Xen will be the future. As you say, the community is bigger and there are situations where Xen is useful and VZ isn't. For that matter, my VPS host has stopped pushing new VZ licenses and they have instead promoted their new Xen packages. True, there is probably a small hit to resources in going to Xen from VS; but compared to the rest of the crap that runs inside a VPS, the "extra" few MBs used to run the extra kernel is minimal. For my web host, it makes sense since the VZ licenses are not cheap; whereas Xen is free (they've hacked up their own management suite).

This would be a REALLY REALLY bad choice.

[namulator]

I myself work on software which uses a VServer modification to the kernel. Although I do see advantages to setting this up so that it's included into the kernel. I see many more problems that this create then the good it would bring through.

Two really big problems I see are these two.

1) There is many other virtual server projects which do the same thing as OpenVZ. If one is included into the kernel, and the others conflict with eachtother over that, that's really going to complicate the linux world.
2) Multiple projects use vserver software currently in project, or they are developing on one of the many different virtual server project. This would cause problems for every one of those peoples project. Companies could loose lots of money because of a foolish decision like this.

The choice should be up to the user, and they should not be restricted to any one server virtualization project. This would get rid of competition over virtual server projects. If they are going to include this virtual server software, they should include all of the current virtual server projects and make them options. Most of them are probably incompatible with eachother, so the code has to make sure those conflicts do not happen.

Maybe an alternative should be to have a patchset made by the OpenVZ which could be given to linux for each kernel release, and multiple trees could be made. A regular kernel, then alternative virtual server kernels.

To allow this to happen would be something like Xorg saying they will only support Intel video cards from now on. Anyone with anything which doesn't have the intel chipset on their video card which is supported is screwed. Or for the linux kernel to only support AMD processors, it just wouldn't make sence. The foolish decision of OpenVZ to request this above all the other server virtualization projects is an extremely greedy and foolish choice I think.

I hope linus says no, or comes and checks the slashdot comments to read this and then tells them no. I may even have to fire him off an email about this.

While I can understand OpenVZ's side of things, overall this would be an extremely bad decision. I hope this never comes to be, for it will be a very sad day.

As for OpenVZ, Quit with the greed, keep your project as a seperate kernel addon to give a more competitive market.

Re:This would be a REALLY REALLY bad choice.

[Slashcrap]

I hope linus says no, or comes and checks the slashdot comments to read this and then tells them no. I may even have to fire him off an email about this.

I may be completely off-base here, but do you by any chance have a massively inflated sense of your own importance?

Re:This would be a REALLY REALLY bad choice.

[gbjbaanb]

I wouldn't mind that - its not as if there's a lack of ego on /. but his comment Most of them are probably incompatible with eachother, so the code has to make sure those conflicts do not happen. tells me he doesn't know what he's talking about, so yes, you're quite right.

For what its worth, reading the other posts on this topic does suggest that OpenVZ is a good thing to have, and would not interfere with other virtualisation systems - OpenVZ is more about process separation than true virtualisation anyway, so would make a good security feature to the kernel, regardless of running multiple VMs on it.

Re:This would be a REALLY REALLY bad choice.

[namulator]

Not really, just being one of the linux community members, I voice my opinions, I don't sit there with my mouth shut and ignore things that go on around me. As long time linux user, when we see something, we talk about it. Thist post on slashdot is the first post in many years. Just because I say I would like to contact Linus with an email or something, doesn't mean I think I am more important then anyone else. Although I may have a better chance because I have been using linux for many many years, I'm a system admin, and I have have an impressive resume considering my age. I do not think in any way this makes me better then anyone else, it's just means I am smart enough to speak up about things I believe need to be spoken about.

Re:This would be a REALLY REALLY bad choice.

[namulator]

I don't have an "ego", I just believe in voicing ones opinions instead of being a sheepie and following what I am told.

If you knew anything about the linux kernel and how these virtualization patches work you would have understood my statement. It is perhaps not me who "doesn't know what he's talking about", but it is you with the limited knowledge of how these work.

For these virtualization patches to work on a kernel, they have to modify key features and code of the kernel. If you had looked into what your talking about instead of reading some other comments and saying "reading the other posts on this topic does suggest that OpenVZ is a good thing to have". How about you use your own mind and think about this for a moment.

If you want to start talking about how the OpenVZ project works, perhaps you should download and look at the patch code. Look at which files of the kernel code if modifies. If you where smart enough to do this, you would see how much of the kernel this code has to modify. The proc code, seg fault code, kernel calls, traces, init code, bios code, cpu code, and much much more. A virtualization project is not some small single option. It has to modify the network code, processor, ram, and swap usage, as well as much other things.

If you had tried to actually use one of these projects, you would see, they are not realy compatible. Go look at all the different linux virtualization projects and try to use them and you'll see what I am talking about.

I offered solutions to this problem. You could create seperatee trees which use the different project, but to go with one will seriously cause problems for all the other projects. Any current software depending on them would be screwed for upgrading the kernel. You must not be any kind of administrator though, because if you where, and you had worked with this and other projects like it, you would understand.

Perhaps you should go do some reading up and figure out how all the source works with the kernel before you start talking about things you have no clue about.

Although a virtualization project I agree is extremely good, but there is more then one. I use a virtualization project in my company, as do many other companies. SWSoft who makes is the maker of this software is a company which makes hosting software. As many hosting softwares, they and many other hosting project use server virtualization projects. For SWSoft to make they version they use the dominating virtualization project, they are putting a kink in any other peoples projects who use other vserver projects to do the same thing.

This would be like microsoft getting intel and AMD to only work on windows operating systems. They would be putting people who use other products at a major loss, perhaps even collapse. Maybe you should look into these types of marketing issues as well as how vserver projects work and are coded into the kernel.

Leaving these virtualization project as external projects is the way I personally think it should remain. This allows more choice and it causes no problems for anyone. If a distribution wants to include it into their distro, they compile the kernels anyway, they can just include the patch as they do now. It makes no difference to the end user at that point. By them putting these changes into the source, it creates the problems I have mentioned. I'm sure Linus will see this on his own though. Perhaps you should go learn some more about what your talking about before you go and start making claims that I don't know what I am talking about. And instead of resulting to trying to discredit my comments with well... "reading the other posts on this topic does suggest that OpenVZ is a good thing to have". Sorry, reading other comments doesn't make you smart. Research the topic instead of just doing what many others have, just comment on something that you really have no idea on.

PS. If all the vserver projects could come together to allow all of them to work around eachother, that would be great, but I

Re:This would be a REALLY REALLY bad choice.

[devovz]

>30% of OpenVZ core patch are changes is mainstream (fixes, security, stability etc.). These are either backported patches or stuff we commit to mainstream. OpenVZ is not worse/better than many other features (CPUSETs, NUMa, memnodes, IPv6 :~) ) which are not *widely* used and has some special purposes, but which still happily coexist with each other.

Re:This would be a REALLY REALLY bad choice.

[namulator]

Ok then, you go apply OpenVZ and any other virtual server project (or all of them) to a kernel and have it work. Good luck! When you are able to do this, then you will be able to say they work together. Until then, you may want to do better research on what your talking about.

Yes, some of the code they are using is probably used used by other virtualization project but you are leaving something out. Each of the server virtualization projects have not been working together. They each impliment things slightly different, and have differences in their abilities and features. Their code is not identical either.

In order to make a patch which supports server virtualization, there are many key aspects of code which are modified. If these projects all came together and decided on setting it up so that all the projects would work together and it was just an option in the kernel to enable which one, that would be awesome, but unfortunatly, that's not what SWSoft is trying to do. They want their version put into the kernel. They don't care about other vserver project, they only care about their own, and their own gets implimented, it creates problems for their competition.

If they could allow all the server virtualizaion project to work together, that would be great, but that's not what is being described here. They want their version to become the one in the kernel. They are not saying that all the virtualization projects should be made into the kernel, they are saying their version should be put into the kernel. Come on, I shouldn't have to explain this to true linux user, they should be able to see through these things, as I hope Linus will do in regards to this project integration request.

If you compile the kernel manually and build your own customized kernel, you would see this. If your a redhat user, or some other distro which makes the kernel for you, you do not need to concern yourself with this issue. If a distro wants to include virtualization into their distro, all they would have to do is apply they patch to their version of the kernel when it is released to a package in the distro software tree. So, users who do that will not be effected by this issue. Only people who know what they are doing and have been custom compiling kernels for years and uses another virtualization projects would be effected by this.

SWSoft uses OpenVZ for their hosting software called Plesk. Other control panels use other virtualization projects. It seems to be SWSoft is trying to make a grab at getting the upper hand in the market by having their project put into the kernel, and not others. If you can't see this, sorry, I have to say I think your being foolish. Each server virtualization project had been designed slightly different, by going with one over the other and including it into the kernel, means the others have big problems, and so does any of the companies which use those other projects.

Each server virtualization project has a different way of managing and controlling the vservers that are setup. Each has different implimentations and setups for pretty much everything they do. Of course all of the projects are going to have some things in common because THEY DO THE SAME TASK!!. If some of the code, as you say, is similar to each other, that is of course beause the projects do the same bloody task. So in order to do something, of course code is going to come up which is similar with other projects, because it's required in order to link those projects into the kernel. You are not looking at the rest of the big picture though. The rest of the project has many differences. The way to enable a vserver, where they are located, what features are setup for them, kind of configuration files control the vservers setup, how the vserver software interacts with all the servers and gets information, and other vserver control structures are completely different.

You impliment one which doesn't work with the others you run into a problem, where everyone who used a different server virtualization

5 (euro)cents worth...

[UglyMike]

My opinion? (as if anyone cares!)

This shouldn't be in the kernel.

-/Most end-users won't care about this technology. For them, Hypervisor is more of interest (whoa! no more dual booting, dude!!)
-/The functionality is more relevant to businesses who have no issue with custom kernels.....but then why not go for something supported/enterprise-grade?
-/It's the crappy freeware version intended to sell the upscale enterprise version. Why put something intentionally crippled in the kernel?
-/ There are several similar technologies being worked at. What makes this entry-version freeware so important?
Now, don't misunderstand me, I'm all for this type of software (even if not as full featured as the commercial package, I would still like to express a lot of gratitude for releasing this). I just think that the people who want to play around with this, will have no problem applying the patch to their kernel. I see NO reason to include this in the kernel.

Re:5 (euro)cents worth...

[ovz_kir]

It's the crappy freeware version intended to sell the upscale enterprise version.

First of all, *please* do not call it crappy -- that way you show your disrespect to OpenVZ developers -- and those guys should be much respected for the efforts they put into OpenVZ and generally the Linux kernel.

To the point -- OpenVZ is very stable and solid piece of software made by the brilliant team of kernel hackers. Whether you like the software or not, have a respect to the people who developed it (unless you are at least as brilliant as they are).

What makes this entry-version freeware so important?

It is what that makes people use Virtuozzo (or OpenVZ) and not Linux-VServer (or FreeVPS, or Xen, or VMware) for their purposes. Compare these products for yourself and find out.

Indeed, this is not entry level software, but a product based on years and years of development and experience. Virtuozzo is developed since circa 1999.

Most end-users won't care about this technology. <...>no more dual booting<...>

To my mind, let the "no more dual-booting" feature better comes from the things such as OpenOffice.

Most end-users will care about this technology because it makes things more secure. I have been to Intel Developers Forum recently, and they showed an example usage case for VT technology -- several instances of Winblows running in parallel -- one for games, one for Internet surfing, one for online-banking. And they told that every single user want this. Certainly it was a demo not a real product yet.

While I was seeing that presentation I though that Virtuozzo/OpenVZ is doing that for years - separate applications from each other. And this is indeed what every user wants - Intel is right - because it strengthens your security.

It's not that simple: everyone is following the $

[mattbee]

Xen has caused major shifts in business direction for commercial virtualisation companies: VMWare suddenly released their VMWare player in part as an effort to make their "virtual machine file format" the standard one. Look they even want to support virtualisation standards now! SWSoft kicked off OpenVZ for similar motivation: because Xen is a competing solution and (they gamble) that it is going to be better to give away a corresponding part of their "crown jewels" to get more of a market share.

Getting your virtualiser into the kernel (or a vendor tree) isn't about control, it's about being in technical pole position to sell copies of their commercial products. Xen might be free, and might have started this all off, but they too have a commercial arm, XenSource, trying to sell Xen Optimizer, presumably as a coda to other products. SWSoft have Plesk, HSPComplete, PEM and others. And VMWare has ESX/GSX server. All of their selling would be made easier, and their marketing departments made very happy, if the king of open source projects, Linux, includes parts of their core technology.

While I'm not sure what the critiera are for acceptance into the kernel, I don't think it's going to happen for SWSoft. From an engineering standpoint, their technology is not much different from Linux vserver which has been around a while to do much the same job and I imagine its invasive kernel changes to keep everything partitioned are just as (un)appealing to kernel maintainers. On the other hand the Xen kernel changes implement a new "architecture", albeit a virtual one, and (last I looked) were only around 150K in size. So I would have thought that the Xen guys have more of a shot at this one because the bulk of their software is maintained outside of the Linux kernel, and seems like the better solution from an engineering standpoint.

But with CPU virtualisation extensions becoming all the rage this year, I think it'll be a while before the best solution shakes itself out engineering-wise: there is still too much vendor "buy-in" for any of these solutions to seem like a good bet for the mainline kernel.

Also NB from the article that SWSoft have made lots of money from selling a modified Linux kernel, and yes for years before OpenVZ they would give out the sources to Virtuozzo licensees. It's not clear to me whether Virtuozzo uses a forked OpenVZ codebase and they are continuing to develop virtuozzo's kernel bits in secret (which would seem like madness on top of running openvz, but that's commerce for you :) ).

Consider this

[Anonymous Coward]

Though I certainly see no need to include it in the kernel and don't want it included in the kernel, realize that many consider one of linux's strong points to be the amount of free software that comes already integrated into the distro's. The /. crowd may not want to see certain pieces of software added to the kernel, but that doesn't mean that it won't help other users and isn't in the best interest of the kernel's quality.

Is it to get ready to GPLv3?

[jetxee]

Earlier SWsoft was playing on a thin age of GPL conformity. Custom modifications to the kernel to enable proprietary kernel modules to work were "GPLed", the real stuff was not (as far as I know). I am sure, OpenVZ was born under the external pressure of the customers, but in the same time, the company was preparing patents, and will certainly use them to squeeze money. So, for SWsoft it might be important to push `free' code into mainstream kernel, before GPLv3 arrives in its full power.

Re:No worries about companies, just about quality.

[Anonymous Coward]

OpenVZ is not an extension of VServer anyhow. It's too much different.
It has fully virtualized network stack with netfilters, 2level quota, etc.

Sharing is not the only thing which makes it more scalable then Xen...
Try to start 100 VMs in Xen with 1Gb RAM. Does it work? No? In OpenVZ it WORKS!

VZ hosting products are interesting

[pyite69]

E.g. http://globalservers.com/

It is like colocation but less expensive. You share cpu & disk with other servers, but it is easier to maintain than a complete dedicated server.

Re:It's not that simple: everyone is following the

[devovz]

Virtuozzo uses the same codebase as OpenVZ.

Re:No worries about companies, just about quality.

[Anonymous Coward]

resource limits and cpu scheduling are part of Linux-VServer for a long time now ...
http://linux-vserver.org/Resource+Limits

OpenVZ versus Zen versus User-mode Linux versus...

[Ed Avis]

There are so many different virtualization projects nowadays. And I keep hearing about magic new CPU features added to the latest Intel or AMD chips which will make virtualization easier than it is today, in some way. Is there a comparative review of the various approaches?

(I still miss running dosemu... that was fun...)