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An Overview of Virtualization Technologies
PCM2 writes "Virtualization is all the rage these days. All the major Linux players are getting into the game with support for Xen, while Sun has Solaris Containers, Microsoft has Virtual PC, and VMware arguably leads the whole market with its high end tools. Even AMD and Intel are jumping onto the bandwagon. InfoWorld is running a special report on virtualization that gives an overview of all these options and more. Is it just a trend, or will server virtualization be the way to go in the near future?"
Is it just a trend, or will server virtualization be the way to go in the near future?
What happened to the CowboyNeal option?
Virtualization is one of the best things since sliced bread and I believe it's here to stay. First of all, it spells an end to multi-booting. I have erased my secondary OSs and I run them in VMs under my main system. A performance hit does definitely occur by I am willing to pay such price for the greater ease of use. Secondly, just think of the possibility to move server images from a physical server to another one, literally freezing it here and awakening it over there - InstaScaleOut(tm) must be a server admin's wet dream.
Of course, as with all abstraction layers, it introduces complexity and takes a toll in the form of performance - but we all know absraction layers have been increasing all the time since the beginning of time.
Global warming is a cube.
We run 2x VM Ware ESX Servers on Sun x4200 servers (w. 8 gig o' ram :) - the web-gui for ESX is second to none, incredibly easy to configure virtual machines. It's got us seriously considering moving more than just our dev enviroments over to virtualised hardware.
With the growing evidence of the human brain's ability to rewire itself and route around failures on the fly, and the effective virtualisation of perception (why do I appear to see a three dimensional picture of the world when I have only 2 curved arrays of photosensors?) we are probably just following a well trodden evolutionary path.
Pining for the fjords
Virtual technology is great you know. I'm using a virtual PC running on a virtual PC which is simulated on the first virtual PC. This is realy a nice solution:
1)Upgrade: simply change a few values in the config and presto! 50Thz processor!
2)No power consuption what-so-ever! I even get a net gain as I run a virtual powerplant.
3)No clumsy hardware on my desk. Just type at the virtual keyboard in mid-air! The virtual monitor can project from anywhere. Heck, they even follow you to the bathroom.
4)No virus, malware or spyware thread! All thanks to the virtual virus scanner.
5)Store up to infinite TB data on the UberDVD drive.
6)Comes with free pron, MP3, warez and Movie server. Complete with anti-MPAA and anti-RIAA card.
Soon to be released: The virtual Car(tm). Just hold up your hands like your holding a steering wheel and make motor sound to get anywhere in the world in just minutes!
Virtual technology. It's everything you ever dreamed of, and more!
I remember the MS vision of making light operating systems which are basically terminal computers and visualizing the OS with remote powerful servers. This way the user will pay monthly/yearly fees to use his computer. Upsides: OS is automatically upgrades with security patches and new features; Data is backed up and can be accessed from any computer. Downsides: Well basically the monthly payment and the fact the MS got your base ;)
I think many companies are looking for a way to monetize software by monthly or yearly fees - this can be their way...
Omgili - Find out what people are saying.
They completely forget to mention User Mode Linux, which is a well established and stable linux only offering, and many of the VPS (virtual private server) hosts you see advertised are running on UML.
It seems that as Xen makes progress, UML is getting ignored.
What kind of article is that?
They talk about VMWare, Intel/AMD, the future Solaris on E10000, other things... but where is IBM?
They can do Virtualization for at least 3 years with their Regatta technology (P670, P690 (Power 4 technology), P530, P550, P560, P570, P575, P590, P595 (Power 5 technology)) and their OS AIX 5L.
they are able to give a few percentage of a cpu to virtual server, with their Virtual IO server, they also are able to virtualize network and disks. They can do workload management between virtual servers. Add/remove disks/cpu/memory in real time.
etc...
So for a complete discussion an overview of the virtualization in the industry, IBM is now a big player, and they are now surpassing SOLARIS & HP in the "closed" unix world.
So for me this overview is not complete and should not have passed the "draft" version until someone was looking at the actual and running alternatives.
L.G.
Comment removed based on user account deletion
Virtualization is finally catching on but please don't make out that this is a 'new' idead.
Virtualization has been built into commercial unices such as AIX, HP-UX etc. for over a decade.
CN=poolmeister.OU=lurkers.CN=slashdot
Haven't got to use it firsthand, but if it's less of a reason to require someone to go into a server room (such as recovering after an OS crash) - it is here to stay.
Dependencies. Package A is tested and certified to run with Foo 1.5 and Bar 2.0. Package B is tested and certified to run with Foo 2.0 and Bar 2.1.
Mea navis aericumbens anguillis abundat
Virtualisation is a disruptive technology... in that it requires a lot of intellectual investment on the part of the sysadmin. The reason Unix and Windows Servers have gotten by without adding much features, yet retaining market share is simple... admin lethargy and apathy.
/client.
Microsoft does not seem to like virtualisation.. hell, they didn't like Terminal Services.. so they crippled it in NT4, made extra licensing restrictions with Win2K, and made the WinXP / Metaframe XP combn. a non-starter. In microsoft's world, users must only license MS's servers and everything needs a separate server
Now that the virtualisation market has grown IN SPITE OF the apathy of these s/w vendors... and the tremendous mindshare with Open Source technologies, these old chaps are trying to make money without doing anything themselves.. witness the recent MS licenmsing options in virtual segments, acquisition of IP, Intel's hypervisor efforts, AMDs efforts etc.
If virtualisation succeeds, it could spell the end for DRM and Treacherous Computing initiatives... since these need collective collusion by all parties involved. Looks like the firms mentioned will try their damnedest to sidetrack virtualisation.. just like terminal servics and thin clients never reached their full potential. Open Source firms and nerdy sysadmins might well have the last laugh...
If you keep throwing chairs, one day you'll break windows....
Don't forget Linux-vserver - it's very good, and very fast - as root in a vserver is root on the actual host - processes just can't "see" or kill any outside their own context. Props to Bertl.
Get your own free personal location tracker
Now guess who said that, and when. :-)
Robert P. Goldberg said that, in 1974.
The fun thing about this is, it's still a very accurate statement. Other than in 1974, though, it doesn't solely apply to mainframes, but, as someone wrote in an earlier post, to everyday computers: desktop systems. I think that's great, and the above quote is more true than ever. Working on Mac OS X and having a Parallels session up and running where some Java application (for example) is tested in a Windows or what environment... lovely.
Yes, I'm a virtualisation enthusiast, if you haven't guessed so already. ;-)
I read the article about Xen, because Xen is what interests me. I'll go back and read the others later. Looks like more of a slashvertisement than anything useful, esp on the Xen writeup.
.. but I am asking the author .. Please don't make something very amazing like Xen disappoint people because you're publishing information you really have not researched that is not accurate.
;)
From TFA:
>> Use the "dd" command to copy the boot drive from another server to a local file, point Xen at that file, and boot
>> the VM (virtual machine). Who needs consultants?
Apparently, the author does, and they have not been reading the Xen devel or user's mailing lists.
File backed virtual block devices can be very problematic for high volume services and applications such as MySQL, Apache and others. Most of us really using Xen on deployments that 'matter' have switched to SANS and using either LVM or real partitions.
Think about how long it takes to create a 3 GB loop device, then copy over the contents over a 10 or 100 meg switch (as you'd find on a hobbyist's desktop).
Migration only takes a few seconds once that's done
If you want to write information on hot topics to draw readers and slashvertise it, great - go for it. Just be sure its accurate.
They also barely touched on what is so magic about running 32 bit guest kernels inside of a 64 bit host, the new Xen credit scheduler, and other really cool things going on with Xen.
If you're going to present yourself as an authority, please present fact, and all of the facts. Please don't setup something like Xen (which many people are working very , very hard on, HP, IBM, Novell, Redhat to name a few) to just dissapoint new users. Nobody would say "Wow that article must have been wrong", they'll say "Wow, Xen is too hard to get working like that article said". Be careful what you capitalize on to sell a few ad clicks
One of the dominate rumors for OS X v10.5 (Leopard) is that it will come with virtualization to run Windows programs. If it did that well (and there are many big IFs to this) Apple may be breaking through. Though, these same rumours suggest MS helped (with Intel) so there must be a poison pill.
If you stat average CPU consumption over the servers of any big size datacenter chances are you will be very surprised by the results.
...
I did this for a company with over 2000 unix servers and averages were : only 20% of the hosts would use more than 30% of the CPU
It's a known fact that for most of the projects the hardware is super sized over what's really needed, and this is one of the main advantage of virtualization : it is seen as a cost reduction process.
With that aggravating beauty, Lulu Walls.
Well, first of all, I'd like to point out that I've run on virtualized systems for the entire extent of my career. Not specifically in the sense which we run now, but in the sense that back in the old days, we ran IBM mainfraim operating systems on IBM systems that actually were virtual machines. They included features such as segmentation and all the good stuff which is just coming around now.
Thanks to other technologies I've run similar systems for ages. It is entirely common for me to develop a file system driver while keeping Mac OS X, Windows, Linux, and DOS running on the same system. I've done this for a long time as well. The difference is that the operating systems would be virtualized by running system emulators instead of using CPU technologies for system segmentation. I did this in the old days under DOS using Quartdeck Desqview and a CPU emulator.
First thing that people really need to understand at this point that virtualization as we're using it today is little more than finding a method to lauch operating systems as "processes" under another operating system. This is not magic, for the most part it's something that any operating system developer should be capable of. The issue is more of grinding. It takes the right kind of people to sit and grind through each of the problems that come up with running like this. It's the same idea as writing a Windows compatible API stack. You start off with simple programs you have the source for and work your way up through more complex applications that require direct hardware access. It's a matter of intercepting the calls and handling them as if you were the real thing.
So here's the deal. As a system level developer, I am more interested in what these guys are actually doing in order to make it happen. Let's face it, although Intel and AMD are adding virtualization technologies to their processors, the actual task of switching between CPU contexts is hardly an issue. The real issue is how are they handling hardware emulation.
See, to me, I focus on high performance workstation related tasks. Servers are cool and great, but in reality, it's how it performs on the desktop that is truly important to me. What I want to see is that a vendor grinds a little more on this issue.
VMWare has classically written device drivers to handle hardware interfacing with better performance than others. So instead of simply emulating the VESA BIOS extensions and providing access to an SDL style frame buffer, instead they have written drivers to allow graphics acceleration. So what I really want to see is that they take it a step further....
I want more than just accelerated BitBlt functions. Of course in the 2D desktop world, high performance frame buffer moves are not optional but required since the bus bandwidth required to copy large frame buffers all around is outrageous. But in the days where OS X uses OpenGL and Windows Vista uses DirectX, I want drivers that interpret 3D contexts as well.
So here's what I'm thinking... write a 3D driver for Windows, Mac OS X, X. The driver should of course offer frame buffer handling, but this shouldn't be the focus since it isn't used for much more than boot and text mode processing. When an OpenGL context is created, instead of creating the context native to the virtual machine, the context should occur on the host operating system and should be managed there. The only interprettation should occur when the graphics driver informs the guest operating system of the top level context.
For direct X, well, I've seen at least one virtual driver in the past which implemented Direct X on Open GL. For professional graphics, Direct X is typically seen as a toy although in reality in many ways it's more powerful than OpenGL (don't argue, it has to do with what's more important to hardware vendors so their drivers are optimized for game based testing). So, since most professional graphics packages are OpenGL based, then the virtualization software vendor should simply implement a translation layer ov
Mainframes have been using virtualisation for decades. It's not going away, it's simply too useful.
Deleted
Its called Google Earth!
Do I misunderstand, or is there are real advantage on running product X in one VM and product Y in another (or even second instance of product X). What is the advantage of that scenario over simply running X and Y (or two X) on the same box.
Well for one, it makes separating X and Y onto different boxes a year down the road pretty well effortless. (whether its for load balancing, hardware upgrades, or whatever)
For another it makes upgrading X possible without having to worry about an impact on Y. Doubly handly in "validated" environments (e.g. FDA regulated)
For another it gives another tool to manage security, as its trivial to partition users and applications.
Not to mention the ability to mix OSes at will (including different versions of the same OS). X has been certified on Debian but not RHEL? Y has been certified on RHEL but not debian? Run that X on debian, Y on RHEL, oh and run Z on Windows 2003, all on one physical box. Very convenient if you need to run 3 low load apps but on different OSes.
Pity that there's not much bad software out there to justify it, then. Oh, wait...
In a survey of 100 programmers, 111111 thought that duck-typing was a good idea.
Isn't that the case with python, perl/parrot, java, ksh, tcl, etc? Any kind of virtual machine will have to have its own DRM, if DRM is to work at all.
http://michaelsmith.id.au
Also, it solves the need for a straightforward rollback mechanism when upgrading windows for application X and finding breakage in this week's MS patch set... Take an image snapshot, patch, test, and simply revert by selecting the prior image. Expect to see more systems running under VM for this and security rollback purposes.
The key point to virtualization that is missed is the ability to seperate the device OS from the user OS. You run a virtualization software to give backwards compatiblity to current OS. The OS sees the devices and thinks they are real. This part is known. Now, there can exists a new market for a device OS, with hardware support instead of software, that doesn't even have to touch the user OS. Linux, Microsoft, Mac, etc all have heavy ties to make the devices cooperate with the users. Instead, the device OS will be in a totally seperate environment. With today's new chips, the device OS could be on a totally seperate processor from the user OS. The user OS uses devices and communicates through portals to reach the device OS instead of directly to the hardware. Security in a system where the devices are seperate from the user OS is greatly enhanced. Rootkits, and like, aren't possible from the user OS. These used to be seperate in the past. That got put together under the same roof. Now, they have started to split up again.
IBM is so far advanced it's not even funny.
Intel and Xen even based their virtualization stuff on old papers from IBM documentation and whitepapers.
You want to know how hardcore IBM is?
THEY INVENTED VIRTUAL MEMORY. And no I am not talking about a swap file on your harddrive, you windows wennie. I am talking about the ability every PC has to abstract memory.. It's IBM's gift to the PC that made modern computing possible.
You aren't convinced of IBM's monsterious power?
They have it setup so that when you buy a OpenPOWER machine for running Linux you can get a optional firmware hypervisor to manage multiple operating systems. And it's pretty cheap also.. For the same price as a low end Sun Opteron box you can get a low end IBM POWER5 box.
But it's not just that... Get this:
IF you buy a Xeon cpu on a add-on card you can set up the machine to RUN WINDOWS.
That's right. Run windows with a fucking x86 cpu on a PCI CARD.. Sharing the same memory and harddrives as Linux running on POWER5. On the same machine. At the same time. With NO slowdown.
Still not convinced?
How about this, for a show of IBM's utter superiority in this feild:
We are running a 2000 era IBM Mainframe with a late 1970's operating system on a 1990's operating system with 1980's era tape drives for legacy reasons.
IT'S A THIRTY-ONE BIT (no NOT 32 bits. 31bits.) OPERATING SYSTEM ON A #$%#$% 64 BIT MACHINE. It's not even like going from x86 to x86-64. They are entirely different computer archatectures. AND it runs at near bare hardware speeds. It's incredable. AND we can run Linux next to it. At the same time. And not just one Linux install, but very literally hundreds of them if we felt like it.
It's completely nuts. They got shit that makes Vmware look like Dosbox. Microsoft's 'Virtual Server' isn't even on the radar; it's completely laughable in comparision.
That and it has the worst possible user interface imaginable. Think about the worst thing you've ever seen. Some DOS 2.x nightmare. Now add a OS/2 GUI and make it WORSE. Now imagine it worse then that. Now your getting close. That and we pay out the ass for the pleasure of using it. Ok, now make it slightly worse. That's about right.
At our place, sysadmins went crazy over all the VMWARE capabilities.
The benfeits are indeed huge, including cutting os intall times to virtually few seconnds, moving live servers from one box to another in case of hw failure, taking server snapshots before upgrading, etc...
What they forgot to think about is that using one virtual server dedicated to every single app (instead of consolidating many apps inside a single os) comes with many downsides, too, esp. on windows:
- licensing costs explode, taking into account AV sw, backup sw, mgmt sw licences
- virtualization eats little cpu per se, but try run 5 AV processes, 5 tivoli/openview/landesk/whatever management client processes on one box, and cpu is toast
- backing up complete server images instead of simple sets of file will easily saturate your lan and storage devices
etc...
all in all it's cool enough, but it comes with many drawbacks, too.
System architecture is changing in a profound way that will somewhat limit the commoditization on which virtualization depends. It's not just a matter any more of CPUs doing calculation and ordering up random disk accesses. RAM speeds, memory bus speeds, interprocessor pipeline speeds -- that stuff all matters a lot now. This is most evident in data warehousing/analytics, where data warehouse appliances (Netezza, DATallegro) and even memory-centric technologies (SAP, Applix) are becoming more important, but it could also be a broader trend.
I've written about some of the details at http://www.dbms2.com/
No way do I dispute the benefits of virtualization in OLTP, messaging, and so on. It's just not the be all and end all.
To err is human. To forgive is good system design.
You say, "good product to support bad software," I say "another tool to use."
If you have a particular problem to solve, and you could solve it with another software release or a virtual server, sometimes it makes more sense just to use virtualization.
It's also handy for load balancing in the sense that you don't want a particular process consuming too many of the machines resources. Virtualization is an easy way to partition a big server's resources. Sure, you could also handle this by increasing the complexity of the software, but why?
- CPUs that can run several microcode architectures, either in parallel or by timesharing between them. Just imagine a CPU with both Intel, SPARC and POWER instruction sets. Yes, yes, there's a lot more to it than just swapping between different instruction sets, but it can be done, and since there has for long been a trend towards making peripherals that can be used in several architectures it shouldn't be too difficult.
Do I misunderstand, or is there are real advantage on running product X in one VM and product Y in another (or even second instance of product X)
Well, yes, it is a nice bandaid for some of the problems of bad software.
However, based on a previous attempt at a physical server consolidation, I can see a big advantage in that you can upgrade/reboot individual applications that live on the same physical machine as other applications without disrupting everything.
Also, it is easier to deploy an OS with specific settings (ie., security settings) in a consistant way.
A house divided against itself cannot stand.
One of my company's clients used VMWare to virtualize the server software we provide them. A few months back they had a massive power outage that caused them to lose large portions of their primary data center.
They weren't running one of our replicated setups, so we were expecting to spend the next week rebuilding the server and configuring our software.
Instead, they grabbed the most recent backup of the VMWare image and booted it up on a completely different server over 100 miles away.
End result?
About a day's lost data and an hour of down time. (The backup was already at the remote site)
I've been pushing for VMWare usage in our test environment to reduce our hardware needs and time spent restoring Ghost images, but a few managers are still dubious, and are afraid we might "miss some hardware issues" if we go that route.
"Live Free or Die." Don't like it? Then keep out of the USA
I see no mention of virtualisation techiques that virtualise a different architecture - such as Transitive's QuickTransit software, of Rosetta fame. They announced a version of their software the other day which virtualises a SPARC Solaris machine on x86-64 Linux, which sounds more interesting than simply pretending to be yourself :)
" To steal ideas from one person is plagiarism; to steal from many is research. "
Security. Modularization. Having one part falling down not take down everything else.
For example, in my setup there are two servers:
* the old one: mysql, postgres, apache
* the new one: Xen
* pound (reverse http proxy)
* postgres
* mysql, apache
* subversion+backups
+ viewvc running as a different user with read-only access to the repositories
* a VM hosted for someone else
When I break the dev apache, the production one stays up. When apache goes down, subversion stays up. When any of my VMs go down, the one hosted for someone else stays; and the other way around.
And when someone pwns anything other than the dom0 (which runs just Xen and ntpd), they took over just that single part.
Sure, I could run everything without virtualisation. But I don't think I have to say why I prefer the way I've chosen.
And you can't claim that Citrix is a good product. Slapping a GUI on a server and "network efficiency" don't belong in the same sentence.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
Various people in this thread have claimed that virtualization is a workaround for not being able to write a decent operating system. I think that's wrong. Different operating systems are legitimately different in the way in which they present high level interfaces and abstractions of low-level hardware features.
What virtualization really is is a long overdue standardization of a set of APIs that exist in many operating systems but remain hidden. By finally exposing them, we gain functionality that didn't exist previously.
Are we talking exclusively hardware virtualization? Because leaps and bounds are being made in OS virtualization as well. Solaris/Nexenta zones spring immediately to mind, as does Virtuozzo
Specialization is for insects. -Heinlein
Virtualization looks like necessary evil, because we are incompetent to write better OSes and Application. Virtualization is the easier route.
It's not a question of "competence", there simply is no such thing as a uniformly "better" operating system or application. DOS, for example, is an excellent operating system for some narrow set of applications, and you can hack Mach or Singularity until the cows come home and you're not going to create something better.
I would have preferred a better, from the ground-up OS any day. Hurd, or ever better Singularity!
People like you are part of the reason why software sucks so badly: you simply don't understand real-world tradeoffs. People like you design systems like Mach or Windows, systems that try to be everything to everybody; people like you throw in MLOCs of useless features and generalizations and extensibility, and all you are doing is create bigger and bigger headaches.
Virtualization is doing the right thing: it lets people focus on creating operating systems and server configurations that focus on solving specific problems. Maybe with virtualization, we can finally kill the general purpose operating system.
ok .. i have been playing around with vmware server for a bit now and no dual booting to test any new distros and what not. i even have a vmware image called dummy terminal with no hd, no floppy, no cd, and only 14mb of ram so i can test ltsp with.
i also see, the possibilities of virtualisation.
i personally am the lead responsible person for 4 servers, 2 with almost 0% load and 2 with 99% load. now my question is this:
is there some way to set up a virtualisation cluster?
i.e. set up a cluster of vmware/xen/blah and have them all share resources, cpu, ram, etc. then create an image that say requires 2 cpus. later when i realise that 99% load on my cpu has been reached (or whatever my threshold) i can "add" more cpus or ram or whatever i want from the resources within the cluster.
i have been dreaming about this for a while now and i want to know if it is possible. if it is possible, what software do i use? and hwere is the documentation to set it up.
thank
_ In Egypt Networks: Network Solutions with a Twist
The thing is you are on gentle path to think different about your network topology, instead of servers doing x,y and z, you have service x, y and z.
That will sneak in to you're machine naming as well, instead of big-frikking-server-doing-it-all. you got fs-01., fs-02., fs-03. distributed by say dfs.
Other example are database clustering, dns, firewalls and webservers.
Now this not a revolutionaire thing, bigger networks always worked this way, but with virtualization, the bigger network can better scale to the needed performance and/or reliability.
Smaller networks can achieve the same abstraction of services vs servers without the cost of it, so it actually comes down to the penny, it saves alot of them, both in hardware and power conusmption.
Maintenance is (when setup right) also easier, so one admin can admin more or has more time to implement advancements (or for bonehead companies, you need less personel).
For the administrator it's the difference between getting a support call of: "I can't get my files and I need them right now!" or noticing that "Hey my nagios reports that some of my distributed services are not responding anymore, better move them to another server before those clusters brakes down, but first let me get a cup of coffee"
Or in short virtualization is less money and more coffee.
The small school I work for is investigating server virtualization because we'll gain exactly what the vendors advertise: better hardware utilization and lower TCO. We can take care of all our needs with a single system and a spare for backups that together cost less than multiple dedicated systems performing the various things we need. Server virtualization is not the best solution for everybody, everywhere by any means, but it certainly fits my organization's needs like a glove.
Even if I knew that tomorrow the world would go to pieces, I would still plant my apple tree. -Martin Luther
Our web-servers partitioned using Xen. We have an apache Virtual machine, an Application Virtual aachine, a database virtual machine. The level of security achievable is close to a traditional cluster environment, at a reduced cost.
Virtualisation is an inevitable step in the evolution of computers. It follows the trend that we've already seen - when computers got powerful enough to usefully run more than one process/program at a time, we introduced multitasking operating systems that "virtualised" memory, IO, and peripherals to multiple processes. Now computers are getting powerful enough to usefully run more than one OS at a time, we are seeing software which arbitrates this in much the same way, and extra hardware features to support it better.
Don't forget that this is just the first or second generation of this technology; in future we are likely to see multiple operating systems on one machine become much more commonplace, and as operating systems start to be built with this in mind, increased inter-OS communication in the same way that we have inter-process communication now.
Also worth noting is that we're moving away from the model of ramping up the clock speed on CPUs and moving towards a model of increasing the number of processing cores (dual-core CPUs and SMP), and smart high-speed switched buses (e.g. PCI express, 1/10/100GBps switched ethernet) - I believe that the computers of 10 to 20 years from now will be highly parallel, modular, hot-pluggable sets of processors and buses that will be able to intelligently allocate and partition resources between OSes and apps, and we will see a break away from the strict two-tier OS/program model and move more towards a much more flexible model with multiple levels of abstraction.
Sometimes is just easier to pinpoint problems when you have an isolated environment, running one, or only related services.
For example, I had lot's of headaches tunning a mailserver running a PostFix+Cyrus+Ldap, plus Apache+PHP+MySQL+IMP webmail. We started with 3000+ users, and it was everything ok until we reached 8000... then all sorts of performance issues appeared, an we could only understand what was going bad when whe isolated the services on separated machines.
A virtual machine is a nice way to do this.
---- You know how some doctors have the Messiah complex - they need to save the world? You've got the "Rubik's" complex
So Sun is marketing BSD jails as a new virtualization technology? What is this, 1999?
Surprisingly, DRM actually likes virtualization. Here's how it works: you make a small, stable and lightweight hypervisor, and a lightweight DRM OS to run under it. You then checksum them at boot through a TPM, and require that they check out to some specific version before the TPM will decrypt your DRMed media.
This is pretty hard to break. Your hypervisor and DRM OS are very small, and can be locked down and checked carefully. Any data not fixed by the TPM checksumming can be encrypted, so you can't hack it by removing the hard drive . You need an IOMMU to shield against DMA attacks from the host OS, but other than that it's very secure.
I hereby place the above post in the public domain.
Horses were cool, coconuts were appropriate technology.
Those guys were genius - inventing Python way before PCs were common.
Busy aligning my non-linear thoughts.
How about failover?
Planned upgrades?
Maybe your redundancy worked, but now requires a shutdown to repair? (Think blade servers).
Maybe the customer wants more power and the current system they're on is maxed?
The live migration in Xen has less than half a second of down time, didn't take much to implement, and solves the problem of squeamish customers who don't want any downtime for any reason.
It makes another option to get around shit that can happen.
Hard to believe that they wrote an article that even mentioned virtualization on mainframes, and didn't think to mention IBM's pSeries solution with runs both AIX & Linux. I ended up going that route over blade servers because it was simply cheaper to implement without sacrificing hardware robustness and redundancy. Not to mention the flexibility of a SAN-backed server....
If foo and bar are a collection of libraries and binaries, then this is a solved problem. http://modules.sourceforge.net/ it really sounds like you are maintaing two OS images because you can't set LD_LIBRARY_PATH :)
-s
Let me guess; you are one of those people who have everything from DNS and DHCP to a database, web, mail, and file server all running on one big SMP box with RAID and all kinds of other redundant goodness, right? I've been there.
1) What do you do when you have to take it down or have a hardware problem? All that stuff stops all at once. With VM's (depending on your solution) you can move services to other machines either live (while they are still running) or at least schedule the move during normal downtime. In the event of complete failure, you don't have to reconfigure much of anything to recover on alternate hardware or in an alternate location.
2) What do you do when you need to upgrade the software running one of the other services? What if you have to upgrade the OS? It's far easier to maintain a couple of machines and handle your dependency problems per application than to try to sort out the web of mess that running everyting in one box gives you. Maybe you like doing that though; go for it.
3) You can prioritize your services more easily. Have a development webserver and production webserver on the same hardware? Sure you can configure it properly and securely, etc. But what happens when you screw up some code and the dev side eats the production side? Whoops.
4) You expose yourself to security problems far more when everything is on the same machine. If there is an exploit for, say, some app you are running on apache, you really don't want every service you run to be compromised all at once.
These aren't all problems that Virtualization necessarily solves though. You can get the same results by using multiple machines, something like jails in BSD, or simply keeping ahead of the game on security and updates and going ahead with everything in one box. VM's just make everything a whole lot easier...
Yes, virtualization is great in the workplace for a couple of reasons, server virtualization as well as the ability to quickly and easily use OS images to test development. However, a huge potential consumer market is out there: a packaged virtualization technology for your mom and pop users, sandboxing their entire connection to the internet on the VM. We all know how your average user has their computer hosed six ways from sunday with viruses, malware, etc. What if we could put their browser/e-mail in a VM so that any viruses/malware/spyware can only hit the OS image? Then all we have to do is revert to the previous backup of the OS image and we're back in business? Sure, the virus kiddies will then try and exploit the VM but it sure seems like a better deal than having to wipe out you entire hard driver, re-install windows and all your applications in order to get back a clean OS.
Well the reality is with MS at least they are opening up to some extent to virtualization. Their license revision to Windows Server 2003 Enterprise grants you explicit permission to run up to 5 (I think) copies of the software on the same machine -- and I believe this is independent of the virtualization layer. I don't use windows for much, but this is a step in the right direction. I don't see many other commercial OS vendors stepping up to do the same.
I remember this kind of argument from Mac devotees in the pre-OS X days when the Mac didn't have real protected memory, and still used cooperative multitasking. People would say that pre-emptive multitasking was just a crutch, that cooperative multitasking was cleaner and potentially more efficient, and that "good" programs would consistently yield processor time in tight loops to let other programs run.
It turns out that putting yield statements in every inner loop of every program you run is a big huge hassle, and that pre-emptive multitasking solves the problem elegantly; so elegantly that everyone does it. Not yielding CPU time is not "bad code"; it's just leaning on an abstraction that you know exists.
This same pattern of argument has been used to downplay high level languages ("optimizing compilers are just a crutch--quality software has hand-scheduled instructions"). Now we'd legitimately have to call the x86 ISA a crutch, since modern processors effectively process x86 instructions in emulation.
Don't fear abstraction! It's good for you.
Application Virtualization is cooler than OS VMs. Microsoft has recently acquired Softricity so lets see they are going to incorporate into Windows Server or as an add-on.
With Windows 2003 Ent you get to run 4 virtual machines at the same time with their "server" operating systems (NT, 2000, 2003) installed in them, at least from the way I read the license. It doesn't seem to say that the "home/pro/workstation" releases are covered.
--
"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
I recently switched my mail/Web server from a G4 running in my basement to a virtual machine at OpenHosting. Previously, I was paying $70/month for DSL with a static IP address; now I pay $20/month for OpenHosting and $15/month for DSL without static IP. And I have someplace off-site to back things up to, and I don't have to worry about the UPS battery running out or the disk drive going kablooey.
:-)
The only downside is that my basement server runs Debian and OpenHosting runs Fedora. But nobody's perfect.
send all spam to theotherwhitemeat@ropine.com
Even with Unix/Linux, you have dependencies on the kernel and database software.
Mea navis aericumbens anguillis abundat
Let's say you have a farm of VMWare servers. You have application A in one VM, and application B in another VM on the same physical server. For whatever reason, the load on application A takes a sharp spike upwards. In your scenario of A and B installed on the same physical hardware, you are pretty limited in your options. Call some poor engineer in the middle of the night, pray you have a spare server, get that app B installed on the new server, and hope everything works. In the VM world, you just grab the VM for either app A or B and move it to a lower utilization server, with no significant downtime. I believe with VMWare 3.0, this process can even be automated to a large degree.
Virtualization has been great for dealing with pesky license servers. Some very expensive software packages require a license server that talks to a hardware dongle. In a university setting, we sometimes run dozens of these license servers. Even worse, most license managers expect the dongle to always be on parallel port one. So with vmware server, we can set up a bunch of dongles on an expansion card, then map each port into the vmware image. Furthermore, each vmware image can have a particular mac address set for it, so even if we have to change hardware or move the license server image around, everything stays set. Dongles are evil. But virtualization makes it liveable. And prevents us from having to have dozens of separate machines that do nothing by run the license software.
User-mode Linux? I've never used Xen in my life – never had any reason for it, and honestly it looks like too much effort for what I'd need it for – but I use user-mode Linux literally every day. Not only is it hosting my Web site (which is actually the reason I've gotten addicted to it), but I've also been using it for software development right on my own machine – since the only machine I have that's suitable for intensive dev stuff is my AMD64, I've set the thing up to run the '64 version natively, and then most of the 32-bit work is done on user-mode. And the nice thing is, it doesn't require any changes to the host kernel, and except for a few special tools for networking, etc., everything you need is right in the kernel source itself.
While I'm on the topic, it's not exactly a virtualization program, but QEMU is also very handy; I tend to use it quite a bit for torture testing new releases, and it's also useful if a certain program won't compile on the user-mode installation because it needs low-level kernel stuff, full POSIX threads support, etc. Even without the KQEMU module it's still faster than the Duron-700/256MB I'd been using before, and considerably more convenient as well.
Anyway, just thought I'd point out that there are other technologies, and other applications as well – servers aren't the only things which benefit from this stuff!
Creative misinterpretation is your friend.
I just like being able to run Windows software on my Linux box without the hassle of Wine. All the best audio tools are written for Windows and I don't like rebooting to use them.
Most of the time I see people using virtualization, it is to get around software conflicts, or to be able to install things side-by-side that aren't designed to be run in that environment. In such cases, virtualization is overkill. They didn't mean to virtualize the entire processor and memory - they only needed to virtualize the system configuration and limited parts of the file system hierarchy.
For these purposes, chroot is a better fit.
I've often wanted an equivalent for Windows, where I could run an application with a virtual registry, so that it didn't muck things up. Or so that it thought it had full access to the C:\WINDOWS folder. Instead, I have to use Virtualization s which requires 2 gigs of space, causes a 2:1 speed reduction, and cuts my available memory in half.
Even better yet, would be decent installers and applications that follow the rules.
--I (and presumably others) would be interested in specifics; what was the bottleneck and how did it work out?
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== WolfriderV6 == I'm willing to admit that *I just might* be wrong... Are you??
No, virtualisation helps DRM... unless you happen to control Ring-0 yourself... and you won't, since Intel/AMD etc are all working feverishly to ensure that they will control it and decide which code gets trusted.
Don't forget IBM's VM/SP (Virtual Machine/System Product) that started on the S/360 series of mainframes; most commonly found running systems like VM/CMS, VM/EMS, VM/XA (basically 3 generations of the same system), or MVS. And, of course, Linux nowadays.
It would (well, still does) virtualize the system hardware into logical partitions (LPARs), allowing allocation of whole units of hardware or factions of it to various virtual machines. Like you'd expect, these LPARs could then run whichever systems they wanted, reboot independently, and so on.
When I left IBM in 1999, all their Toronto Lab "mainframes" (6 or 8) were really just different LPARs on a single piece of hardware... at headquarters. They weren't even physically present at the Lab. (And air-cooled too, so no more going home early just because TOROLAB4 developed a leak in the main cooling pump.)
They've since ported the LPAR concept to the pSeries (former RS/6000), so you can run multiple configurations of AIX and/or Linux on a single machine, and move hardware resources from LPAR to LPAR as your load on the different VMs change.
They do something similar internally for their "Virtual Loaner Program". It looks like you're getting a whole machine to yourself--with root access and everything--but, of course, it's just an LPAR on the appropriate hardware, with the system you ordered (AIX or Linux) pre-loaded on it. (Which is really an AMAZING way to get more pSeries hardware if you're in a crunch because Critical Customer #1 just opened a deal-breaking ticket and you need to get development time on a slightly older version of AIX RIGHT AWAY... don't ask me how I know.)
Well,
At first we had issues with the IMAP access, it was too slow, we thought that it was because of the authentication backend... but in the end was because we set a low limit on how many IMAP processes should be spawned by the cyrmaster. We removed the limit, and the IMAP became blazing fast.
But, we still had an occasional slowdown. It turns out that the HORDE groupware we're using to provide webmail was not designed with performance in mind, so when you throw lots of requests at it, the database backend is flooded with tousands of queries. It happens because when you do anything inside Horde it has to do some sort of query... So, MySQL was handling about 1000 queries/s!
Solution? Split the critical services among several servers...
---- You know how some doctors have the Messiah complex - they need to save the world? You've got the "Rubik's" complex
I'd rather use linux, but need to run Adobe Acrobat (not the reader, the full version). Damn thing doesn't work under Wine/CrossOffice (as far as I could tell). So that leaves me with virtualization option. What's the easiest option to get it to run? VMware?
And this is just an illustration of what some posts here are claiming: virtualization is a very crude way of solving a problem that many applications aren't programmed to support existing OSs & hardware setups.
We're running what I believe is an embedded form of Win2003 Server, with an Admin session feeding out to client sessions. There's some real power hitters on this thread, and I'm more of a nuisance-fixer, not a server admin.
But the construction software company Sage, maker of Timberline, has confirmed that the differences in the design of the hardware virtualization interferes with the Timberline software. My manager is less than thrilled, and is seriously considering changing server designs.
So, our one-case sample has shown some real frustrations.
--TaoPhoenix
My first Journal Entry ever, in 8 years! http://slashdot.org/journal/365947/aphelion-scifi-fantasy-horror-poetry-webzine
I don't mean to take anything away from IBM. They have answers to questions
most (maybe all) of the competition doesn't even know they should be asking
in regards to VM.
but: No, IBM didn't invent virtual memory. I believe the first commercial
machine with virtual memory was from Burroughs. A weird stack-based box
(FORTH is what it is in part because its developer used a Burroughs) that
pushed the envelope of the day mighty hard.
That said: I have fairly fond memories of IBM VM. Not so fond memories
of the OS's I was using under VM but fond memories of VM nonetheless.
Scary accuracy. Virtual Cardpunches that were compatable down to the
bugs against specific models of IBM physical cardpunches.
Have you ever heard of an instance where anyone is not running crappy software? ;-)
As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
good news is, the guys behind Xen are really spot-on, and the project has a real chance of breaking through into mainstream usage similar to how vmware did about 4 or 5 years ago
bad news is, xensource, one of xen's biggest supporters, just appointed Larry Augustin of va linux systems [fame/infamy] to their board of directors, a guy responsible for ripping the proverbial rug out from underneath several OSS projects and screwing the respective developers of those projects over the years from what i have heard. I seem to recall "there's a special circle of hell set aside for guys like him" when his name came up
i wish the xen folks luck
Sorry but if you don't mention IBM here then clearly you haven't done your homework.
I downloaded the PDF of this work and found one instance of IBM anywhere in the text. One. How lame.
InfoWorld loses on this one, incomplete research. I can virtualize the hell out of my IBM Systems be it System i, System p etc. They all do it, and no InfoWorld it isn't just all about VMWare & Virtual Server, although I personally do like VMWare.
I once had another journalist tell me they didn't include IBM because it was just known that they do this stuff well. Ok so why not mention it? You present this like these are the only players in this game.
GM.
Microsoft probably danced around terminal services inclusion for fears of antitrust complaints from Citrix.
Let's say I need to run a bunch of database servers, but each one must be quarantined for security reasons. I can go out and buy 100 servers, which will idle most of the time, or I can by a few high end servers and run virtual machines, saving on real estate. And backup and restores are a snap....
And of course it's not a fad. There are already a lot of server farms out there that are highly dependent on virtualization. It allows them to provide specific OSs, and even OS versions (notice that Sun is mainly interested in letting folks run multiple versions of Solaris), without dedicating a machine to each installation. Less expensive, more flexible. No big mystery there.
And it's not even a new idea, though this particular implementation of it is. For years, supercomputer companies have sold software that divided their multiprocessor systems into "cells", each running its own OS. Virtualization is pretty much the same thing, only it doesn't require a dedicated CPU — or the purchase of an expensive supercomputer.