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

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?

[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.

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?

[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?

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...

[Dr. Evil]

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

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?

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

[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.

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: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.

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?

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: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.

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).