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Work Underway To Return Xen Support To Fedora 13

kdawson posted more than 4 years ago | from the how-many-xen-buddhists-does-it-take dept.

Red Hat Software 93

Julie188 writes "Details on this are admittedly sketchy, but both Red Hat and Xen.org have gone on record promising that some kind of support for the Xen hypervisor is forthcoming for Fedora users. As we know, on Monday, Fedora 13 was released, chock full of features to appeal to business users. One of the ballyhooed improvements to 13 is virtualization — meaning KVM and only KVM — for Red Hat. Xen was dropped from Fedora a few releases ago and it hasn't come back in 13, except that 13 still supports Xen guests. Meanwhile, 'work is underway in Xen.org to add platform support to Fedora 13 post-release,' promises Xen.org's Ian Pratt."

cancel ×

93 comments

KVM catches Xen (4, Informative)

Pecisk (688001) | more than 4 years ago | (#32345456)

As more new servers are deployed for virtualization, Xen superiority over KVM slowly, but surely disappears. First of all, all new tech has virtualization acceleration support in CPUs. Now, for example, using KVM in combination with paravirtualized network and storage drivers (which are packaged and used in Ubuntu as default), Ubuntu Server 10.04 LTS has the same speed and performance as guest as using Xen. Also huge improvements into libvirt stack and virt-manager have played role here - yes, I know, Xen also can use libvirt, but still - as it is more and more easier to deploy virtual machines, be it development or server environment. I have worked with Xen exclusively in the past for some three years, and most problems have been kernel patching issues and in fact, HVM support (because you still have to emulate some devices with quemu, which leaks like crazy, I guess that's reason why KVM now uses paravirtualized devices for net/storage). I don't have time to compile code for production servers, so if KVM is in kernel, and it is supported by kernel team and distribution, I will go for it. I was reserved And I guess lot of newcommers in virtualization will too.

In nutshell, Xen devs shoot in the foot here. Have they agreed to be included in main kernel three and be more welcome with patches, it would be more interesting competition here.

Re:KVM catches Xen (5, Informative)

hax0r_this (1073148) | more than 4 years ago | (#32345594)

I was responsible for maintaining a Xen environment for about a year and a half and had much the same experience. We compile our own kernels and in this regard Xen was a nightmare. Do I stick with a 2.6.18 kernel which is the latest supported? If we do that we have to make sure to get backported security fixes. Or do we use forward-ported Xen patchsets which weren't all that reliable and were a pain in the ass to apply?

We finally switched to KVM and suddenly life got a lot easier.

(Going slightly off topic here)For a while we used libvirt and the associated tools, then we discovered Ganeti [google.com] , a project at Google which has made cluster management a breeze. Libvirt has a "network" driver, but really isn't designed to manage redundant virtualization clusters. Ganeti, on the other hand, is designed specifically for managing clusters, and takes care of all the dirty work like setting up and managing LVM and DRBD. You can build out a new virtual machine, complete with an operating system in just one command, or even do it over the HTTP API. You can use Ganeti with KVM or Xen, but until/unless Xen is in mainline I won't be touching it.

Re:KVM catches Xen (2, Informative)

Anonymous Coward | more than 4 years ago | (#32346356)

I rolled out a small number of KVM virtual machines at a remote site (6000 miles remote), and looked at Ganeti to manage them. It looked good, but in practice it was designed for much larger clusters than we had, and in the end it just flat out didn't work. It also didn't help that KVM has apparently only been supported since Ganeti 2.0 was released and that the documentation is very Xen-centric.

After a little more research I became a little disappointed by the current state of virtualisation tools. They're either incredibly simple GUI's to qemu for manageing one or two Qemu disc images on your desktop machine or huge complex beasts like Ganeti that are so specialised to the original authors that they're almost impossible to fit into anywhere else. In the end I just wrote a few simple scripts that could be used to clone & manage KVM instances which were no more than a couple of tens of line of Bash each, and we called it done. Sure it isn't a large scale virtualisation platform (we use VSphere 4 for our core infrastructure) but it works.

Re:KVM catches Xen (3, Informative)

pasikarkkainen (925729) | more than 4 years ago | (#32347542)

Some comments.. Xen hypervisor (xen.gz) is not meant to be integrated to Linux kernel. Xen is designed to be a separate piece of software. Xen is a secure, type-1 baremetal hypervisor, not a module for Linux. Xen dom0 ("service console") can be Linux, NetBSD or OpenSolaris. Most people use Linux as Xen dom0. When Linux is used as dom0 it needs to be able to run as Xen dom0 (obviously) - and this is where some people have had pain. For a long time the official Xen dom0 kernel patches were only available for Linux 2.6.18. This was difficult for many people and caused some distros to drop Xen dom0 kernel support because they couldn't affort porting the patches to newer kernels themselves. Today the situation is different. Xen developers are actively working on rewriting the Xen dom0 patches based on the (already existing) upstream pvops framework. pvops has been in the upstream Linux kernel since 2.6.24. Xen pvops dom0 patches are available today for the long-term maintained 2.6.32 kernel, and also for 2.6.31, 2.6.33 and 2.6.34. Novell has also forward-ported the old/traditional Xenlinux patches from 2.6.18 to first 2.6.27 and also to 2.6.31, 2.6.32 and 2.6.33. So there are many options today. For more information about the various Xen dom0 kernels see: http://wiki.xensource.com/xenwiki/XenDom0Kernels [xensource.com] Also xen.org offers XCP (Xen Cloud Platform) which is a full platform, including installation CD and multi-host/pool management. If you use XCP you don't need to install custom kernels or anything - you get all included in the XCP bundle. More information about XCP: http://www.xen.org/products/cloudxen.html [xen.org]

Re:KVM catches Xen (2, Informative)

0100010001010011 (652467) | more than 4 years ago | (#32347704)

Not every OS shuns Xen as a Dom0 like Linux seems to. I run Open Solaris this is what it took to get running:

pfexec pkg install xvm-gui
pfexec svcadm enable milestone/xvm
pfexec reboot

That's it. I wanted to use Linux. I read every single manual I could. There seemed to be 10 different ways to do the same thing and the documentation was never quite there. I could just never get it working the way I wanted to.

With virsh and virt-manager setting up another OS is cake. I'm running Debian64 as DomU and Windows7 under HVM.

Re:KVM catches Xen (1)

drsmithy (35869) | more than 4 years ago | (#32348474)

That's it. I wanted to use Linux. I read every single manual I could. There seemed to be 10 different ways to do the same thing and the documentation was never quite there.

Well that's pretty much Linux <anything> in a nutshell. ;)

Re:KVM catches Xen (1)

badkarmadayaccount (1346167) | more than 4 years ago | (#32364064)

My hope is to get Xen in mainline for a quasi-microkernel. Though it would take some work - here is my initial concept - libfuse and <insert favorite fs her> as a domU guest, linux as dom0, and exporting the fuse kernel module interface as a vdev. Think about it - native ZFS and NTFS performance, no licensing issues. Don't forget - Xen is based on the Nemesis microkernel. And that's just the beginning... Any takers? I'm not much of a programmer...

KVM is also compatible (4, Interesting)

thule (9041) | more than 4 years ago | (#32345656)

Plus, KVM has xenner that provides Xen compatible devices to virtual machines. I also saw some patches going into KVM that provide Hyper-V hypercalls to KVM. Right now they are fairly basic, but it is a start.

There is no doubt that KVM is the future. It is built into the kernel -- no dom0 patches required. RedHat is heavily investing in it. Note the sponsored oVirt project that integrates libvirt and FreeIPA to manage a network of virtual machine servers using kerberos and ldap as the security framework.

Re:KVM is also compatible (1)

Hurricane78 (562437) | more than 4 years ago | (#32346878)

Last time I looked, KVM was orders of magnitudes slower than everything else. Has that changed now? I want something that at least beats Xen.

Re:KVM is also compatible (2, Interesting)

thule (9041) | more than 4 years ago | (#32347766)

I'm guessing the only reason KVM was slower was because it didn't have special virtual drivers. It does have block and network drivers now, but NO video drivers. Since KVM is more focused on server performance than graphics I have never had an issue with the graphics speed.

Someday KVM may catch Xen (1, Informative)

Anonymous Coward | more than 4 years ago | (#32346436)

I've been using virtualization on non-x86 hardward for over 10 years. The ideas are not new to me.

I've used VMware, Xen, KVM, QEMU, VirtualBox, LMU, Jails, on Linux-based and BSD-based installs.

I started testing KVM in our lab about 6 months ago to be ready for the releases that have all come out recently. I've not been impressed. Performance sucks when compared to Xen and that is putting it nicely. Xen is lighter than VMware and VirtualBox. I don't really care about the controlling tools provided the CLI commands work. We have custom commands for Xen that can easily be migrated to KVM.

We're not going to use any virtualization that isn't part of the main production distributions, so Xen appears to be on the way out for us. I hope that KVM performance becomes similar and that the default setup matures to provide reasonable defaults with reasonable performance. Sadly, if I had to deploy new production VM infrastructure today, it would be ESX.

Someday KVM may catch Xen, but it hasn't yet, at least in the current packaged repository releases.

Re:Someday KVM may catch Xen (1)

OeLeWaPpErKe (412765) | more than 4 years ago | (#32346994)

Is ESX so much faster than VirtualBox ? In my experience VirtualBox beats VMWare in quite a few areas (though, sadly, not in networking). And the most recent version, 3.2, with fully asynchronous I/O widened the gap further.

It's almost to the point that having virtualbox run a VM in a file on ext2 beats VMWare running the same VM with it's "partition filesystem" in normal setups.

Re:Someday KVM may catch Xen (2, Informative)

Thundersnatch (671481) | more than 4 years ago | (#32347290)

Is ESX so much faster than VirtualBox?

Yes, it is. At least it was in all of our internal testing, and every published benchmark I've ever seen.

In my experience VirtualBox beats VMWare in quite a few areas (though, sadly, not in networking). And the most recent version, 3.2, with fully asynchronous I/O widened the gap further. It's almost to the point that having virtualbox run a VM in a file on ext2 beats VMWare running the same VM with it's "partition filesystem" in normal setups.

Are you comparing VirtualBox with VMware Server or VMware Desktop? VMware ESX/vShpere are completely different products. VirtualBox may in fact out-run the lower-end, OS-hosted VMware Server and VMware Desktop. But in general, it won't come close to anything from the VMware ESX/vShpere product line (which is a hypervisor that runs on bare metal).

Re:Someday KVM may catch Xen (1)

OeLeWaPpErKe (412765) | more than 4 years ago | (#32347496)

Actually ESX is a hypervisor that runs on an old redhat distro last time I checked. Given the featureset of the newer VMWare's it would amaze me if half of them (specifically the "new" hardware support) isn't just the result of a linux kernel upgrade.

Have you found a lot of benchmarks online ? I've never seen more than a few, and I would require relatively recent versions of the hypervisor (vSphere 4 vs VirtualBox 3.1 or 3.2 preferably) to be compared to find such benchmarks relevant.

But I'd appreciate a few links with recent benchmarks if you have them. A simple google (VirtualBox versus ESX is not yielding much, except forum discussions. Not that they aren't interesting, but I'd appreciate a few raw, hard numbers)

Re:Someday KVM may catch Xen (3, Informative)

Thundersnatch (671481) | more than 4 years ago | (#32347740)

Actually ESX is a hypervisor that runs on an old redhat distro last time I checked. Given the featureset of the newer VMWare's it would amaze me if half of them (specifically the "new" hardware support) isn't just the result of a linux kernel upgrade.

No, the VMware ESX hypervisor runs on bare metal. The management console for ESX is based on an old RedHat, but that just talks with the Hypervisor via an API. In fact, the ESXi version doesn't even have the management console, and you use the VMware client to manage the hypervisor.

But I'd appreciate a few links with recent benchmarks if you have them.

I'll see what I can dig up, but comparing VirtualBox to ESX isn't frequently done because they're so different. I recall that I saw benchamrks comparing VirtualBox to VMware desktop, and then benchmarks comparing ESX to VMware Desktop, and did the transitive analysis.

Our internal tests threw out VirtualBox (and VMware Server) as options after very simlpe IOmeter benchmarks. They were both dog-slow compared with ESX.

Re:Someday KVM may catch Xen (1)

OeLeWaPpErKe (412765) | more than 4 years ago | (#32348944)

Our internal tests threw out VirtualBox (and VMware Server) as options after very simlpe IOmeter benchmarks. They were both dog-slow compared with ESX.

Under which versions was this evaluation made ? Vsphere 3 or 4 ? VirtualBox 2 ? 3 ?

Re:Someday KVM may catch Xen (1)

Thundersnatch (671481) | more than 4 years ago | (#32349544)

I think it was Vmware ESX 3.5 (u1 I think) and VirtualBox 2.0 on Windows X64. It was mid-2008, so it was whatever was current then.

Re:Someday KVM may catch Xen (1)

jackspenn (682188) | more than 4 years ago | (#32350404)

ESXi version doesn't even have the management console

At server (or via ILO or DRAC connection) Hit Alt+F1, type unsupported (don't worry if you see nothing on screen just keep typing), login as root user with password and there is your console.

- Eric

Re:Someday KVM may catch Xen (0)

Anonymous Coward | more than 4 years ago | (#32347576)

> > Is ESX so much faster than VirtualBox?
> >
> Yes, it is. At least it was in all of our internal testing, and every published benchmark I've ever seen.

Do you work for VMWARE?

Re:Someday KVM may catch Xen (1)

Thundersnatch (671481) | more than 4 years ago | (#32347822)

Do you work for VMWARE?

No, I don't. We went down the VMware ESX route several years ago and have been very happy. The product has very few warts and limitations, and is rock-solid stable. Our ESX hosts stay up for months at a time.

Now, VMware's pricing leaves a lot to be desired, but when we looked into the projected operational costs of basing our virtualization project on anything else (Xen, Hyper-V, KVM), the excellent management tools and support from VMware made it the least-cost and least-risk option. We run about 70 VMs on five VMware ESX hosts.

Re:Someday KVM may catch Xen (1)

OeLeWaPpErKe (412765) | more than 4 years ago | (#32349642)

You are working for VMWare.

VMWare's support redefines "non-responsive", and their products come out with bugs that makes you wonder if they've ever run them even once themselves [zdnet.com] . Their pricing is so ridiculous you can say without blushing "I'd rather have a mercedes". And it's yearly, so you can easily have a quite well-paid full-time engineer on staff instead of VMWare enterprise.

And this is just one example of a bug. If you look at the lists of bugs that prevented windows booting, caused extreme slowdowns or simply made the management unreacheable, there's no shortage of such bugs at all.

Of course you could argue that with all other products if you lock yourself out of the console you've done it yourself, but still. And of course KVM has no shortage of absurd slowdown bugs (having run it, I do wonder how anyone dares call this monster a triumph of kernel hackers).

Everyone screws up. But why don't I leave you with a bit of VMWare advice on running your server :

"Customers should not stop virtual machines. Keep virtual machines going until we release a patch," Niemar had said. "You can also move the clock backwards on the server."

Re:Someday KVM may catch Xen (1)

Thundersnatch (671481) | more than 4 years ago | (#32349872)

VMware's support has been quite good for us, but then again, we paid for platinum. We actually haven't needed them too much, only for some VLAN tagging issues.

As for the licensing server bug... meh. It didn't hurt us, because we don't run on the bleeding edge version-wise. All developers screw up on occasion. We waited for the patch before upgrading to 2.5u2 plus patch at the same time, testing it in our QA cluster first. Virtualization stacks are still software that has to be managed and tested properly in your own environment.

All in all, VMware is one of the better software vendors I deal with. Leaps and bounds ahead of many.

Re:KVM catches Xen (2, Insightful)

shallot (172865) | more than 4 years ago | (#32346454)

In nutshell, Xen devs shoot in the foot here. Have they agreed to be included in main kernel three and be more welcome with patches, it would be more interesting competition here.

Why, yes, they have agreed to include their patches in the main kernel tree, but not all of them have the consent of the upstream kernel developers. The response of the Xen developers has been a significant refactoring of their code. Try reading the readily available documentation on the progress of merging Xen kernel patches upstream [xensource.com] .

Re:KVM catches Xen (0)

Anonymous Coward | more than 4 years ago | (#32348272)

I used vmware on windows for a few years. Not very user friendly, but it works.
Then i used vmware on Linux for about a year. It worked but was more pain to setup. But the really painful thing was to reconfigure it every time a new kernel comes up.
I tried Xen in Fedora. Big pain, and in the end it did not even work!
Then I tried virtualbox. It worked on first try.

For me a virtual environment should be installed and upgraded via mechanisms such as yum, and should not require constant reconfiguration.

So for me so far virtualbox is perfect.

This is an understatement (0)

Anonymous Coward | more than 4 years ago | (#32349102)

+10. I used to be a REAL big fan of Xen. Did development work on it, and did some amazing stuff. Been to a number of the Xen conferences. Then I ran into Xen Cloud Platform. That converted me to KVM and I will never go back.

XCP is the most inane POS I have ever seen. The bad designs of Xen magnified by 10. In essence, the Xen developers have abstracted the System level interfaces, which has resulted in reinventing the wheel, needlessly and as badly as one can get. My general impression is that a bunch of Application programmers have decided to write an O.S. without the slightest clue as to what they are doing. Jeezus, Citrix, you need to put the Systems guys in charge first, and the Apps guys second. Apps guys are often dangerous in that they think they know System level work. Not doing this always leads to problems, and you are a prime example of what not to do. There's an old saying: Those who don't understand UNIX are doomed to reinvent it, badly. And that's exactly what you are doing.

The Xen guys shot themselves in the foot by essentially trying to fork Linux, by blowing off keeping up with mainstream. Now they are trying to repeat this again by creating a half-baked distro. C'mon guys, get a friggen clue. There's a reason why people do things the way they do it, and not the way you do it.

Stay away from Xen Cloud Platform. I'm looking forward to the KVM equivalent. At least there I know the Apps guys won't fancy themselves as OS people. And the OS guys will get things right, like they usually do.

Awesome (-1, Offtopic)

bmecoli (963615) | more than 4 years ago | (#32345460)

The Vortigaunts shall be pleased that Fedora 13 supports their home world in an alternate dimension.

Hi (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#32345478)

Pro-tip: When your website claims that it's a news site, don't start articles or summaries of articles with the word "so."

Re:Hi (2, Funny)

Aeternitas827 (1256210) | more than 4 years ago | (#32345496)

Protip: Look for the quotation marks, it's a quote, not added by the person publishing to the frontpage.

Re:Hi (0)

Anonymous Coward | more than 4 years ago | (#32354142)

Slashdot has "editors" for a reason.

Cool story bro (1, Offtopic)

MrEricSir (398214) | more than 4 years ago | (#32345598)

Protip: The word "protip" is not hyphenated.

Re:Cool story bro (1, Offtopic)

timmarhy (659436) | more than 4 years ago | (#32345608)

Pro-tip: protip isn't a word.

Re:Cool story bro (-1, Offtopic)

MrEricSir (398214) | more than 4 years ago | (#32345692)

Protip: In the English language, words enter the language through common usage, not a central authority. The word "protip" comes from GamePro magazine.

Re:Cool story bro (1)

Mister Transistor (259842) | more than 4 years ago | (#32345714)

Well, I've never read GamePro, and never heard "Protip" used in my region, so AFAIK it's not a word.

Protip: What you give a hooker if she's REALLY good.

Re:Cool story bro (2, Funny)

mrclisdue (1321513) | more than 4 years ago | (#32346104)

Protip: Apparently, anyone can embiggen the English language, cromulently, whenever one wishes....

cheers,

Re:Cool story bro (0)

Anonymous Coward | more than 4 years ago | (#32348016)

so if you've never heard a word used in conversation, it's not a word?

Re:Cool story bro (1)

Mister Transistor (259842) | more than 4 years ago | (#32349798)

By the same token, you can't just invent a word and say well, there - it's been "commonly used" so now its a word.

Just because one gaming mag uses it for it's l33tspeak doesn't make it "popular" or widespread, at least not from where I'm sitting.

I tire of people trotting out the "common usage" defense daily here, in defense of what is usually local slang. In order for your cult to be a religion, you gotta have followers!

Yes, it's true we don't have a Central Authority for Proper English, but more than a select crowd of gameheads needs to adopt the usage before you can claim the "common usage" defense, IMHO.

Re:Cool story bro (0)

Anonymous Coward | more than 4 years ago | (#32353874)

I would debate this with you, but half your diction bonked with my demographamily several months ago; I refuse to stoop to your ludditic, anti-emancipational insistubborn use of Q1 2010 verbage when the new global paradigm has so clearly anointed the synergistic fusion of Q2 2010 diction.

Re:Cool story bro (1)

bsDaemon (87307) | more than 4 years ago | (#32346678)

your right, its two whole words, each independent of each other, yet acting in harmony out of unity of purpose.

Re:Cool story bro (1)

LBArrettAnderson (655246) | more than 4 years ago | (#32354152)

You can hyphenate whatever you want. Putting "pro" (short for professional) and "tip" together happen to create the same definition as the word "protip" (which isn't actually a word).

Xen needs to improve (4, Insightful)

Alain Williams (2972) | more than 4 years ago | (#32345580)

I liked the idea of Xen and tried to use it for some time, however:
  • The (free) management tools were bad. If you wanted to do anything other than something quite simple, it was hard or impossible
  • The documentation was hopeless: not complete; not enough examples; out of date

An exciting technology that I hoped to use, but just not up to the mark.

Re:Xen needs to improve (1)

shallot (172865) | more than 4 years ago | (#32346430)

Is this the right place to add more anecdotal "insight"? :p

We're using it at work in dozens if not hundreds of hardware and software combinations, and it's not exciting at all, it just works. We use only its free management tools and rely only on its freely available documentation.

HTH, HAND.

Re:Xen needs to improve (2, Informative)

pasikarkkainen (925729) | more than 4 years ago | (#32347814)

This has changed pretty much lately. A lot of new documentation has been written to the wiki, for example: http://wiki.xensource.com/xenwiki/XenCommonProblems [xensource.com] has a lot of stuff and links to other new documentation pages. Have you heard of XCP (Xen Cloud Platform, http://www.xen.org/products/cloudxen.html [xen.org] )? It's a full "Xen distribution" featuring install CD, including everything needed for multi-host/pool management. No need to install custom kernels or anything. You can use OpenXenCenter (http://www.openxencenter.com/) to manage it, if you need a GUI tool.

Where it belongs... (5, Insightful)

Chris Snook (872473) | more than 4 years ago | (#32345618)

Fedora, not RHEL, is really where Xen belongs anyway. It's exactly the sort of mix of neat ideas, dirty hacks, and blatant wheel re-invention that could only have come from academia, and it was only ever made enterprise-grade by throwing heaps of money at it, and even then only for carefully tested configurations. Yes, it's pretty much single-handedly responsible for commoditizing virtualization, but the combination of the design and the lack of cooperation with the kernel community made it a nightmare to support. Xen is responsible for the existence of KVM because it showed such immense promise, and then delivered extreme frustration and pain.

Since Xen decided long ago it was going to be the center of its own universe, it's really in a great position to do cool experimental things that the kernel community would be more cautious about and the enterprise market wouldn't touch with a 10' pole without seeing a strong proof of concept first. That kind of innovation is a stated goal of the Fedora project.

The only technical advantage Xen enjoys right now is a lack of dependency on hardware virtualization features. Since it's impossible to buy a new machine that you can call a server with a straight face that lacks hardware virtualization, this is meaningless in the enterprise world, but Fedora (like other community distros) has a much broader scope, so there's still a real chance there for necessity to give birth to more invention, much like it did in the early days of Xen when x86 hardware virtualization was still a whisper in the halls at Intel and AMD.

Of course, Xensource/Citrix has already driven away most of the community that would have done this kind of pre-product development, so I'm not holding my breath, but it would be nice to see something more to come of all that work (and years of my own life) beyond simply supporting existing users.

Re:Where it belongs... (1)

Engeekneer (1564917) | more than 4 years ago | (#32345770)

The only technical advantage Xen enjoys right now is a lack of dependency on hardware virtualization features. Since it's impossible to buy a new machine that you can call a server with a straight face that lacks hardware virtualization, this is meaningless in the enterprise world, but Fedora (like other community distros) has a much broader scope, so there's still a real chance there for necessity to give birth to more invention, much like it did in the early days of Xen when x86 hardware virtualization was still a whisper in the halls at Intel and AMD.

I do agree with the post in general, but I wouldn't belittle the fact that XEN doesn't need hardware support. I have already been affected by the dropping of xen from distributions. I do work in academia, so I have to work with older, but completely functional machines.

We've tried to set up our own interal eucalyptus cloud, but ran into trouble when it wanted to use KVM by default (can't recall which installation this was). Also for other basic virtual machines, we'd need HW support, which we don't have in most machines.

While I'd gladly use KVM instead of XEN, I can't and I think I'm not the only one. I welcome the avaliability of xen, and think dropping support for it is a bit premature

Re:Where it belongs... (1)

Viol8 (599362) | more than 4 years ago | (#32346444)

"Also for other basic virtual machines, we'd need HW support"

Why? Just use vmware or similar.

Re:Where it belongs... (1)

Engeekneer (1564917) | more than 4 years ago | (#32346758)

Why? Just use vmware or similar.

Well we'd still need some kind of performance. Of course qemu / vmware would work, but the performance difference vs xen is pretty huge.

Re:Where it belongs... (1)

pasikarkkainen (925729) | more than 4 years ago | (#32347918)

From the new enterprise distributions Suse Linux Enterprise 11 (SLES11) SP1 fully supports Xen, including the new Xen 4.0 hypervisor, and Linux 2.6.32 based dom0 kernel. OpenSUSE also has Xen included/supported. Upcoming Debian 6.0 ("Squeeze") will also have Xen (including dom0).

Re:Where it belongs... (1)

Chris Snook (872473) | more than 4 years ago | (#32359644)

I don't mean to belittle the significance of Xen's paravirtualization approach, but rather to point out that it's much more suitable for environments like the ones that tend to use Fedora than the ones that tend to use RHEL. Xen tried to be a commercial product way before it was technically ready for it, simply because there was so much market demand for commodity virtualization. Maybe it's ready now, but I wouldn't know, because I gave up on it as soon as KVM reached feature parity, because it didn't require understanding a totally separate technology and keeping up with a totally separate development community. If Xen really has come a long way since then, they've still got a lot of catching up to do, because KVM hasn't stood still.

Re:Where it belongs... (1, Interesting)

Anonymous Coward | more than 4 years ago | (#32346090)

f you think hardware visualization is fast, you guys need to revisit what hardware virtualization is and how KVM, Xen, Hyper-V implement it.
Please do not jump to conclusions without knowing the concepts and implementation.
Paravirtualization is faster and a much better approach. Do some benchmarks yourself and you will know. Have some of your VMs run in HVM mode, run benchmarks. Then deactivate HVM and use paravirtualized kernel for the VMs and run the benchmarks again.... you will get pretty conclusive results.

I am talking about Linux on Linux .... I have not done any experiments with Windows on Xen/KVM so not sure.

Now the maintainence part, you are right on.. Xen is a hell to maintain. But we all know speed comes with a compromise.

Re:Where it belongs... (1)

Chris Snook (872473) | more than 4 years ago | (#32359668)

For one generation of CPUs, you're right, hardware virtualization was slower. Since then we've gotten hardware nested paging that eliminates the TLB penalty and virtio device drivers that give us paravirtualization in confined I/O devices without having to coordinate the entire memory space between guest and host.

KVM decided to be stable first, THEN fast, and it succeeded. Xen decided to be fast first, THEN stable. The results are a clear lesson in the ills of premature optimization.

Re:Where it belongs... (0, Offtopic)

shallot (172865) | more than 4 years ago | (#32346482)

... a nightmare to support ...

... extreme frustration and pain ...

... market wouldn't touch with a 10' pole ...

You sound like you have an axe to grind.

Re:Where it belongs... (1)

Chris Snook (872473) | more than 4 years ago | (#32359734)

Yes, I have an axe to grind. I worked in support for Red Hat back when RHEL 5 was released, before the switch to KVM. There were rumors going around engineering about switching to KVM as early as RHEL 5.1, because as unready as KVM was at the time, Xen was a disaster. We shed enough blood to get Xen usable until KVM had good paravirt I/O, so that got deferred for a few updats. Prior to leaving Red Hat Support, I'd get bug reports from customers, and track down patches in xen-unstable that were summarized with "Linux does this a different way, so we probably should too." That kind of insight-free crap doesn't fly on LKML, and it further goes to demonstrate the sort of wheel-reinvention, endemic in Xen, that belongs in a research labs and not enterprise products.

The first two comments you quoted were my own opinions, and yes, they're a bit jaded from my experience. The last comes from the customers I dealt with. Xen was popular among the customers in industries that were doing cost-cutting. For the financial services customers, who simply wanted to squeeze as many logical servers as possible into their data centers next door to the exchanges, money was no object, so they stuck with VMware, because it was cheaper to have consultants tweak the hell out of their setups than switch to a faster paravirtualization product that just wasn't absolutely rock solid.

I no longer work there, but last I heard those financial services customers were much more interested in KVM than they ever were in Xen. The trading systems still run on bare metal, with realtime kernels where possible, but for all their other systems they want to virtualize everything they can, and KVM's technical advantages over VMware are quite compelling. Xen enjoys the same higher CPU and memory counts, but the stability problems were a deal-breaker.

Re:Where it belongs... (1)

shallot (172865) | more than 4 years ago | (#32451426)

product that just wasn't absolutely rock solid.

I no longer work there, but last I heard those financial services customers were much more interested in KVM than they ever were in Xen.

This doesn't really make much sense, as it goes against the conventional wisdom of software development - newly written or younger software by default scores worse on the stability front compared to old software, even if old software was known to be buggy - exactly because of the simple fact that someone somewhere already dealt with many of its quirks, and hopefully put it in order, whereas there is inherently less proof that anyone ever did that with novelty software. There are exceptions, obviously, but I don't think it's common among people who want rock-solid stability to be betting on getting such an exception.

Re:Where it belongs... (1)

Saint Aardvark (159009) | more than 4 years ago | (#32347076)

Of course, Xensource/Citrix has already driven away most of the community that would have done this kind of pre-product development, so I'm not holding my breath

I'm curious (genuinely curious, not being snarky)...I've had a bad experience with Xen too, but I haven't kept up with what Xensource/Citrix have been doing. Why do you say they've driven away the community?

Re:Where it belongs... (0)

Anonymous Coward | more than 4 years ago | (#32347784)

I find the comment curious about Citrix driving away the community. In fact, the Xen community has grown larger since the acquisition of XenSource by Citrix. The community is now seeing great efforts from new partners such as VALinux, Fujitsu, Samsung, and Oracle to name a few. We are also seeing a large increase in university research being conducted with Xen and those efforts are being brought back into mainstream Xen development tree. If the person posting has specific examples of where Citrix is driving away the community I would love to hear about them as I believe the opposite to be true.

Stephen Spector
Xen.org Community Manager

Re:Where it belongs... (0)

Anonymous Coward | more than 4 years ago | (#32348432)

VALinux? It still exists?

Re:Where it belongs... (1)

Chris Snook (872473) | more than 4 years ago | (#32359602)

In fairness to Citrix, I think the situation has improved somewhat since the acquisition, as evidenced by the fact that it's even possible for Fedora to be considering this move now. That said, I think it's a day late and a dollar short. Xensource alienated the Linux community prior to that acquisition and Citrix has done little to repair that damage. In my opinion as someone who was forced to support Xen for Red Hat prior to their acquisition of Qumranet, the Xen community has grown primarily because existing users have increased their use of virtualization, not because of significant new deployments of Xen.

I'm glad to hear that you have significant university participation in the community, because I absolutely mean what I said about Xen being in a good position for research, but unless there are some drastic changes soon, I suspect Xen will rapidly lose the enthusiasm of the industry partners it needs to remain a credible enterprise product as customers migrate to KVM and other virtualization technologies.

XEN on Linux - use Oracle Linux or OpenSUSE (0)

Anonymous Coward | more than 4 years ago | (#32345740)

If you want XEN on Linux, then it is better to get Oracle Linux or OpenSUSE where XEN is included. It is really quite good and OpenSUSE has an excellent admin GUI for the whole system.

Can someone explain the point of hypervisors? (2, Interesting)

Viol8 (599362) | more than 4 years ago | (#32346386)

Seems to me they mostly get used to run multiple OS's that each run a single main app. Last time I looked modern OS's are quite capable of running multiple apps at the same time so unless you really need to run different OS's on the same machine (er why?) then what exactly is the point?

Re:Can someone explain the point of hypervisors? (0)

Anonymous Coward | more than 4 years ago | (#32346834)

Advantage 1: tunability. You can tweak each VM to suit its single application even if they have conflicting requirements.

Advantage 2: repairability. If you break the VM in fiddling with its guest OS, you can easily load a new one and try again. None of the other VMs are damaged. Ditto if a VM gets rooted.

Advantage 3: rationing. When I last did this for Solaris zones, it was easier to apportion the CPU cores and memory between VMs than it would be between apps running directly on the host. YMMV.

Advantage 4: ports. If you need 20 web servers each on port 80 that are 20 distinct sites, then you probably don't want 20 boxes. We got to this when we wanted multiple copies of Tomcat and didn't want to got to ports 808x. (Yes, I know Apache httpd and Tomcat each can do virtual hosts, but the VMs were easier.)

Advantage 5: software distribution. You can pack guest OS + app into an "appliance" to get round portability problems.

Re:Can someone explain the point of hypervisors? (1)

spydum (828400) | more than 4 years ago | (#32350482)

I'll cut you some slack: 1,2,3 and 5 are certainly valid points for why virtualization/hypervisors. 4 is completely non-sense. Virtual hosting or aliased IP's is far more manageable than one VM per site. The only exception might be if you need customer isolation, but even that can be accomplished without virtualization.

My main value out of hypervisors is the detachment from hardware dependencies. If I can upgrade server hardware without affecting my "servers", by effectively just reallocating or migrating a VM to another host, my job as an admin is remarkably easier. Additionally, much of the HA and resource optimization (memory dedupe and such) abilities of hypervisors nowadays make it significantly more effective to run more apps with less hardware, while still being able to provide redundancy and availability.

Re:Can someone explain the point of hypervisors? (4, Insightful)

betterunixthanunix (980855) | more than 4 years ago | (#32347074)

Here is a scenario for you: you have some old server that is going to be decommissioned, but it is running some important software, and perhaps a different operating system from all of your other servers. On the one hand, you can go ahead and configure a new system...or with virtualization, you can simply take a snapshot of the hard disk image and run a VM on some other server (perhaps one that is underutilized).

In general, the point of virtualization in a server room is flexibility. VMs are easy to move around, you do not have to be tied to a single operating system (I hear the most common use of KVM is to run Exchange on system with a Linux hyperviser) on a single physical machine, which is particularly useful for sharing hardware resources when you have to deal with software that only runs on a specific OS. VMs also make it easy to checkpoint a system; KVM has "copy on write" disk images, for example, which track changes from a base image, which could be a COW image itself.

IBM did a lot of research on virtualization use, and I believe they had discovered uses for using VMs within VMs up to four layers deep (I am not really sure what they were doing).

Re:Can someone explain the point of hypervisors? (1)

phantomcircuit (938963) | more than 4 years ago | (#32350084)

I believe they had discovered uses for using VMs within VMs up to four layers deep

Space heater?

Re:Can someone explain the point of hypervisors? (1)

Shimbo (100005) | more than 4 years ago | (#32347172)

Seems to me they mostly get used to run multiple OS's that each run a single main app. Last time I looked modern OS's are quite capable of running multiple apps at the same time..then what exactly is the point?

It can make management of large numbers of machines easier. If you've got half a dozen applications on a machine, owned by different groups, it can be a nuisance to manage upgrade cycles. Some groups may buy their own little servers to get around the problem: with virtualization, you can let the development folk can run their server, *and* host it in the data centre.

Another useful thing is splitting off the hardware support issues from the application support ones. Need to roll out a critical BIOS update across a bunch of servers: live migrate the running VMs off to a spare host, put them back afterwards.

Re:Can someone explain the point of hypervisors? (3, Insightful)

thePowerOfGrayskull (905905) | more than 4 years ago | (#32347380)

It's harder to see when you're not at the enterprise level. Picturing being tasked with providing 10,000 identically configured desktop PCs that are intended to run a limited subset of applications in a locked-down manner.

You have two choices. You can use actual desktop computers -- power-hungry, subject to failure at that number, and generally expensive to maintain at that scale. Or you can use VMs - a fairly small number of physical servers. Your desktop component can be a simple thin client device -- cheap, power efficient, much lower likelihood of failure, and - when they do fail - much simpler to manage as it takes a few minutes to replace the physical device. Your user never knows the difference, as he still connects to the same VM. If someone screws up a VM, you just rebuild it - an automated process that takes a few seconds. Compared to a PC which can require someone to physically be present at the machine; and at the very least will take 10-20 minutes to copy down the hard drive image over a network.

Now let's say you're expanding - another 2000 users. With desktop PCs you have to order PCs -- hopefully no major changes in hardware since you last ordered, because then your client apps need to be re-certified. Then you have physically image the hard drives to the standard image; then deploy and set up the hardware at each workstation.

On the other hand, if you were using VMs you would add 20-40 servers to the cluster and bring the VMs online. The configuration is completely automated, with a human being required only to press "go". You still have to purchase the thin client devices, but even considering the new servers you bought, the cost is *far* less than buying 2000 PCs. Too, it doesn't matter if the specs change on the thin client devices, because their sole purpose is to connect to the VM. The ongoing cost remains much lower, and setup consists of plugging it in and flashing the ROM. (Though at that size, there's a fair chance you can work out a deal with the manufacturer to do it for you.)

As far as personal/desktop use - good for testing apps on different OSs, and playing with new OSs. Also good from a security perspective (run your web browsers in a VM, and questionable software. Roll it back daily or whenever you think there's been a compromise.) Also good if you're running Linux but have a couple of needed apps that don't work on WINE.

Re:Can someone explain the point of hypervisors? (0)

Anonymous Coward | more than 4 years ago | (#32349516)

What kind of thin client do you typically use in this case?

What is your virtualization software?

Re:Can someone explain the point of hypervisors? (1)

thePowerOfGrayskull (905905) | more than 4 years ago | (#32349806)

In our environment we're using Wyse terminals; though the development team typically uses desktops as the VMs don't have the horsepower. In that case we'll connect to VMs for testing via MSTSC (since we're a Windows shop for our call center client software).

Virtualization is ESX server.

Re:Can someone explain the point of hypervisors? (0)

Anonymous Coward | more than 4 years ago | (#32360630)

Ever needed another machine to test an idea? Cloning a golden master VM images takes seconds and uses no additional hardware. Works great for functional testing (although VMs sometimes sacrifice a little in performance). Ever need a clean environment to build a package. Once again, a VM makes that quick and painless. Many times I just boot an Ubuntu LiveCD, apt-get the packages I need (in seconds from our local fast mirror), and away I go on a new project without ever setting up an image at all. Hibernation allows my state to be saved. In other words, you can think of VMs as reducing the "edit-compile-link cycle" but for whole servers or environments.

I also find myself using VMs for monitoring. Wish you knew what is going on in the network (or why the network behaves oddly)? Fire up a VM and run tcpdump or other tools. In fact, I keep an XUbuntu LiveCD ISO image around just for that purpose.

BTW, I also use containers when I am doing variations on the same (linux) theme as it is even lighter weight. I have also used VMware Server/Player/ESXi, VirtualBox, KVM, Xen, and pure even Qemu/kQemu back in the day. I am migrating away from VMware now that the OSS alternatives are mature. (I loath the Server 2.x interface and the scripting API to ESXi has been shedding needed features lately.) Our server guys prefer Xen. I prefer VirtualBox and KVM for desktop use. Having Xen in the kernel would probably add it back to my desktop list.

I am working on finding a good way to virtualize network switches so I can build complete virtualized ecosystems. Not been able to get VDE to do what I want. OpenVSwitch looks promising though.

Anon

Re:Can someone explain the point of hypervisors? (1)

badkarmadayaccount (1346167) | more than 4 years ago | (#32364848)

Here's a business idea - single purpose, hardware specialized X11 servers getting SCSI RDMA over Ethenet. Run Windows HVM Xen guests on server side, with FBSD/ZFS on dom0, with ro snapshot of the system partion of a base system, with each ~/ on a separate vdev. You still pay Windows licenses, but management is simplified, hardware upgrades as well. Run that on a ATAoE San, and your golden. The only non-commodity part is the thin client - probably a customized ARM SoC with a tweaked GPU. Oh, and to save on licensing - DIY Win7 terminal sever [blogsdna.com] . Though that would require making only the boot files in the snapshot, and creating a directory junction with a context sensitive (ala HP-UX) filesystem (NFS tweak?) (see IFS in Windows) on a different partion on the same vdev as the user data. Each user sees his own version of the filesystem, and that version is contained in a single snapashotable vdev.
Yes, I am in high school, yes I am virgin, and yes I am out of weed. :P
Hope this seems interesting to you guys. I love OS architecture, though I'm not a programmer. X)

Re:Can someone explain the point of hypervisors? (1)

badkarmadayaccount (1346167) | more than 4 years ago | (#32365352)

Sorry for replying to my self, but it realized that with virtualized hardware and Win7 registry virtualization, my approach isn't nearly as intersting as when applied to XP, so there [golod.com] . Hell, you can go crazy and offload TCP connections to the host with an appropriate driver and virtio Ethenet dev. Why the hell run a firewall and shit when you can use a much more powerful TCP stack to begin with.

Re:Can someone explain the point of hypervisors? (1)

drsmithy (35869) | more than 4 years ago | (#32350326)

Seems to me they mostly get used to run multiple OS's that each run a single main app. Last time I looked modern OS's are quite capable of running multiple apps at the same time so unless you really need to run different OS's on the same machine (er why?) then what exactly is the point?

Isolating a single application to a single server is the ideal situation. It dramatically simplifies change management, troubleshooting and dealing with special requirements.

All modern OSes are, indeed, quite capable of running multiple apps. However, similarly, all of them are also dismally bad at isolating them in an easily manageable fashion - hence the explosion in popularity of virtualisation.

Errr... what? (1)

StuartHankins (1020819) | more than 4 years ago | (#32346964)

We recently purchased RHEL 5 Advanced Server after a few months of trying out Red Hat's virtualization options. One of the questions we had was whether Xen or KVM was the right tool to use going forward -- because we didn't want to adopt something then have it be replaced by new shiny almost immediately afterwards. We want to use a single virtualization platform for all our servers which means a migration from ESXi. I had already setup Xen and was starting to benchmark it.

We were emphatically told by several people at Red Hat (2 salespeople, our dedicated support engineer, and 2 other support staff) that Xen was the wrong direction and that only KVM would be supported in the future AND that existing support for Xen was being phased out. Yes I know Fedora isn't RHEL -- I've used Red Hat since 5.2 (way before Fedora Core). But this is just confusing and reminds me of the days when Red Hat Workstation was marketed.

Re:Errr... what? (1)

betterunixthanunix (980855) | more than 4 years ago | (#32347104)

It seems that Red Hat is only going to support KVM in RHEL, regardless of what the Fedora community does. Really, that is not so uncommon -- Fedora has a lot of things RHEL does not have (look at the "spins").

RHEL6 supports running as Xen guest (1)

pasikarkkainen (925729) | more than 4 years ago | (#32347748)

RHEL6 will support running as Xen guest, both PV and HVM. You can use RHEL5 as the Xen host (dom0), and run RHEL6 guests on it.

Re:Errr... what? (1)

suso (153703) | more than 4 years ago | (#32347230)

I can tell you know that it really doesn't matter what you choose. It will eventually be replaced by something shinier and more popular/modern. Such is the way of computers and especially in the open source world. IMHO, KVM became popular because a bunch of people who weren't really using Xen decided that they liked it better and didn't give consideration to the real issues at hand. And now that they've started using KVM for real work, they are running into those issues and regret the whole thing. I've had a heavy investment in Xen since 2005 and its worked well for me and will continue to work well. But I don't really care about all that GUI management stuff, I just wrote my own. What it really comes down to is what can you live with? Do you have servers that are handling thousands/millions of transactions per day? Or are you just running a departmental webserver with just a few users? If you're doing something intense, then its worth your time to test the technologies out for yourself and see which one works better. You can test Xen vs. KVM for free.

Re:Errr... what? (1)

StuartHankins (1020819) | more than 4 years ago | (#32347688)

Do you have servers that are handling thousands/millions of transactions per day? Or are you just running a departmental webserver with just a few users?

Since we're using RHEL AS, which starts at $1500 per year, it's not a departmental webserver.

When we started testing KVM in the initial RHEL 5 release, KVM setup was needlessly difficult -- both Xen and KVM were installed, a Xen kernel was selected by default, and dom0 was setup and started automatically. You can imagine my confusion as a new KVM user.

Now it's just the opposite, as of 5.5 it appears that KVM is the simpler choice. It also seems to be much faster -- although there was a tweak to our network cards that I discovered during KVM testing that I hadn't applied during Xen testing.

Since support is important to us, we definitely don't want to go with a vendor-obsoleted track. In our world, this first Red Hat hosted production VM is running POS software that everyone in the company touches. Providing the Windows server testing continues to go well, we are planning to transition up to 10 or 11 other blades to RHEL AS also.

Yes there is always new shiny and at some point everything is always replaced -- BUT when your vendor is telling you "don't implement this, it's already being phased out" you'd be silly to ignore that. For an org of our size, that action would be deemed irresponsible.

Re:Errr... what? (1)

diegocg (1680514) | more than 4 years ago | (#32347564)

It's mainly Xen who is trying to get Xen supported in Fedora 13, more than the contrary. If the Xen guys manage to get Xen merged in the kernel Fedora probably won't have problems enabling it or offering alternative packages to use it. But KVM is still the focus.

RHEL5 fully supports Xen (1)

pasikarkkainen (925729) | more than 4 years ago | (#32348366)

RHEL5 will fully support Xen until 2014 (which is when RHEL5 goes EOL). Redhat has stated this multiple times. Also upcoming RHEL6 runs as Xen guest, on RHEL5 Xen host/dom0. So there's no need to switch away from Xen.

Re:RHEL5 fully supports Xen (1)

Dog-Cow (21281) | more than 4 years ago | (#32352128)

Unless, you know, you can see further than 4 years down the line.

Re:Errr... what? (1)

b0bby (201198) | more than 4 years ago | (#32348666)

We want to use a single virtualization platform for all our servers which means a migration from ESXi.

I'm curious as to the advantages of moving away from ESXi - I'm in a much smaller environment than what yours sounds like, but I've been happy with ESXi for all the guests I've run on it (Windows & various Linux distros). Before spending real money on it, though, I'm looking at other options. To me the ESXi hypervisor idea seems great - next to nothing running on the box means less to go wrong etc. The VSphere stuff seems to give all the bells & whistles I would need, and the price isn't excessive for the scale I'm dealing with. What will the RHEL setup give you?

Re:Errr... what? (1)

StuartHankins (1020819) | more than 4 years ago | (#32350160)

The biggest reasons are the primary systems we want to virtualize are RHEL5, so I want to stick with an RHEL5 host; and ESXi only uses 4 cores, which is not enough for our terminal servers... our uses are starved for CPU time while the blade itself is only partially utilized. In general ESXi has been great until we get a heavy load, then there are issues. Other reasons -- relayed to me by my VM sysadmin; I'm just the Linux guy -- include the need to re-convert to copy a VM and its reliance on a proprietary filesystem which makes getting those images out a bit difficult. With RHEL you can just copy it wherever.

While ESXi looks nice and is a great free solution, we have grown more and have reached the point where we need to either go full vSphere ($$ for software to manage the 10-12 blades) or some other solution.

The hardest part will be migrating the ESXi VMs to Red Hat. Right now there's no "official" way to do that although you can find tips using Google. I'm told that's forthcoming this winter.

The Red Hat solution isn't trouble-free: its built-in tools lack the GUI management and monitoring prettiness and simplicity of ESXi. (16-core machines appear as 4 or 5 screens wide using System Monitor and can't be made less wide, so you have to install kdebase and all its stuff to use KSysGuard and then customize it pretty heavily. Disk stats are ugly and by default the VM adapters are vnet0, vnet1 etc so make sure you change that in the VM config files so you can track what's happening. GUI tools and virsh sometimes gets out of sync although it's better than in 5.4 and prior.) Lots of other little things that need to be worked around, but when it's setup correctly it works great. Even on a test desktop-class machine (running Werewolf of all things) where we made a VM of a Windows 2000 DC, it worked well.

We (very briefly) looked into the Red Hat hypervisor version, thinking (like you) that a small easily installed host would be ideal for DR. But it still uses a Windows server (!!) to manage them. We want a single solution from a single vendor and basically asked them to let us know when that's ready so we can review it.

Re:Errr... what? (1)

b0bby (201198) | more than 4 years ago | (#32366672)

Thanks for that - I hadn't thought of the 4 cores issue. I have been a little frustrated with the difficulty of moving images around, though. Maybe I'll dig out an old server & do some playing with alternatives, I have a buddy who loves Xen but I haven't done anything with it or KVM.

Re:Errr... what? (1)

drsmithy (35869) | more than 4 years ago | (#32350364)

We want to use a single virtualization platform for all our servers which means a migration from ESXi.

You're crazy to be moving away from ESXi, then. Especially to RHEL, where the builtin management capabilities around virtualisation are pathetic, to say the least.

We were emphatically told by several people at Red Hat (2 salespeople, our dedicated support engineer, and 2 other support staff) that Xen was the wrong direction and that only KVM would be supported in the future AND that existing support for Xen was being phased out.

This is correct. Xen will be supported until RHEL5 is phased out, KVM is the (current) long-term platform.

Citrix alternatives? (1)

arndawg (1468629) | more than 4 years ago | (#32347490)

Are there any competitive KVM solutions compared with Citrix's XenServer? The ease of management is great in Xenserver. Al tough ironically it's IMO harder to use Linux guests than windows guests since they only support a limited set of distros (and versions). If i want to run gentoo in a xenserver enviroment that's a lot of work with swapping kernels and grub config etc. That's just not feasible so i'm forced to run Cent OS, which I kinda dislike. Alternatives out there? How good are standard KVM tools?

Re:Citrix alternatives? (1)

pasikarkkainen (925729) | more than 4 years ago | (#32347722)

Did you try XCP (Xen Cloud Platform, http://www.xen.org/products/cloudxen.html [xen.org] ) ? XCP 0.5 is coming out in June.. you can manage it using OpenXenCenter (http://www.openxencenter.com). Basicly XCP is XenServer opensourced and developer further..

Re:Citrix alternatives? (1)

arndawg (1468629) | more than 4 years ago | (#32347914)

Ooh, neat. i'll check it out. Thanks.

Xen support in Fedora 13 (1)

pasikarkkainen (925729) | more than 4 years ago | (#32347640)

Fedora 13 contains Xen hypervisor and tools, but it doesn't contain rpm package for a Xen dom0 capable kernel. There are unofficial Fedora rpm packages for a Xen dom0 capable kernel, based on the upstream pvops dom0 kernels (Linux 2.6.32). More information about Fedora Xen status and links to rpms see: http://fedoraproject.org/wiki/Features/XenPvopsDom0 [fedoraproject.org] . More information about available Xen dom0 kernel options see: http://wiki.xensource.com/xenwiki/XenDom0Kernels [xensource.com] .

I stopped caring about Xen when... (1)

Dishwasha (125561) | more than 4 years ago | (#32347670)

I saw a live virtual machine migration across processor families and types [youtube.com] . Wish they would release that tech soon rather than work on getting Xen support back.

Re:I stopped caring about Xen when... (1)

pasikarkkainen (925729) | more than 4 years ago | (#32347712)

I think that has been already supported for a while in Xen..

Beh (1)

Hognoxious (631665) | more than 4 years ago | (#32347976)

Does this version of glibc.x86_64 make my butt look big?

Good (1)

Errtu76 (776778) | more than 4 years ago | (#32348942)

Maybe this will force the Xen people to write maintainable code so we don't have to keep using 2.6.18 and backport everything.

Re:Good (1)

pasikarkkainen (925729) | more than 4 years ago | (#32351496)

Xen dom0 patches are available for 2.6.27, 2.6.29, 2.6.31, 2.6.32, 2.6.33 etc..most people prefer 2.6.32 atm, since that's the long-term maintained kernel from both kernel.org and xen.org. For more information: http://wiki.xensource.com/xenwiki/XenDom0Kernels [xensource.com] . Xen developers are also busy preparing (and rewriting) the Xen dom0 support for the mainline Linux Xen pvops framework, which has been in upstream Linux since 2.6.24.

It's here, now (1)

bill_mcgonigle (4333) | more than 4 years ago | (#32353776)

Use the myoung dom0 repo. I've been running a Fedora 12 Dom0 for a few months now.

I so want to like KVM, but it's still fragile. I'll continue to help file and test KVM bugs so it's better than Xen at some point.

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