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Xen 4.1 Hypervisor Released

Posted by Soulskill on from the onward-and-upward dept.

LarsKurth writes "The Xen.org open source community just released a new version of the Xen Hypervisor, Xen 4.1. Feature highlights include a new prototype scheduler for latency-sensitive workloads, better support for very large systems (>255 CPUs, 1GB/2MB super page sizes), new security features, and many others. During the development cycle of Xen 4.1, the Xen community worked closely with upstream Linux projects to ensure that Xen dom0 support and Xen guest support are available from unmodified Linux distributions. The release announcement contains a full list of changes."

105 comments

  1. Hope for an improvement. by Anonymous Coward · · Score: 0

    The last version was so full of bugs it was nearly unusable, including some that disabled the keyboard on some of our machines.

  2. Isn't Xen dead? by darthcamaro · · Score: 0

    Ever since IBM stopped contributing this Xen two years ago, the pace of Xen development has been pathetic. Not sure why this project is still alive.

    1. Re:Isn't Xen dead? by ecliptik · · Score: 2

      Oracle is trying to enter the x86 virtualization market with Xen in a product called Oracle VM. I've used it, and it's ugly. Besides the PHB marketing tagling of "you can run Oracle on the entire stack!", I've seen no technical reasons to use it over KVM or VMWare in the enterprise.

    2. Re:Isn't Xen dead? by Anonymous Coward · · Score: 1

      Ever since IBM stopped contributing this Xen two years ago, the pace of Xen development has been pathetic. Not sure why this project is still alive.

      Amazon (arguably the biggest cloud service provider) uses Xen exclusively.

    3. Re:Isn't Xen dead? by h4rr4r · · Score: 2

      Because they have not noticed that IBM abandoning them and KVM removing the need for them means they are dead. Give them time.

    4. Re:Isn't Xen dead? by DiegoBravo · · Score: 1

      But why not use its own Virtualbox? I find it a lot more usable than Xen. Well, anything is easier to use than Xen.

    5. Re:Isn't Xen dead? by Apu+de+Beaumarchais · · Score: 1

      Oracle is trying to ENTER the x86 virtualization market with Xen in a product called Oracle VM. I've used it, and it's ugly. Besides the PHB marketing tagling of "you can run Oracle on the entire stack!", I've seen no technical reasons to use it over KVM or VMWare in the enterprise.

      You keep using that word. I do not think it means what you think it means. http://www.virtualbox.org/

    6. Re:Isn't Xen dead? by DCFusor · · Score: 1
      VB's what I use here, and I like it fine myself. Just to be able to use windows on a linux box for certain things like embedded programming IDE's. Works well (after a small amount learning), lets my program PICS via USB, sound works, serial works, it all just works.

      Here's hoping Oracle doesn't start charging for it -- just after releasing some updates the mess up the free version. But you know they will, being Oracle and all. I suggest keeping older versions of the packages in case they do that. After all, if all you need is to run XP for some things, or a few spare linux distros -- you don't need to change the VB platform, ever, unless a new one has new features you need.

      --
      Why guess when you can know? Measure!
    7. Re:Isn't Xen dead? by fuzzyfuzzyfungus · · Score: 4, Interesting

      I'm pretty sure that Virtualbox and Xen are(in addition to architectural differences) aimed at substantially different uses of virtualization.

      Virtualbox, though there is nothing specifically stopping you from using it otherwise, is pretty much aimed at the "second and/or test OS on primary desktop" use case. Run whatever primary OS, run a small number of secondary OSes or virtual test boxes because RAM is cheaper than a rats nest of towers and KVM switches. This shows in the fairly simple configuration, easy support for peripheral-passthrough and graphical guest OS window, and lack of interest in things like automated guest migration.

      Xen, by contrast, is aimed much more at the "pool of VM servers supporting some large number of VM instances that are mostly there to interact over network only" style. Nothing prevents you from setting up your desktop as the dom0 OS, and using it like Virtualbox; but it would be a pain and not clearly beneficial. On the other hand, you get much more concern for large memory spaces, guest migration, and similar things.

      This isn't a precise analogy(since I suspect that they share somewhat more, just for cost reasons); but asking "Why use Xen when you could use Virtualbox?" is sort of like asking "Why use VMware ESX when you could use VMware Workstation?"

    8. Re:Isn't Xen dead? by ecliptik · · Score: 1

      Virtualbox is their consumer x86 virtualization product, Oracle VM is their x86 enterprise virtualization solution; clusters, high-availability, etc.

      Think of it like this:

      Virtualbox = VMware Workstation
      Oracle VM = ESX/vSphere

    9. Re:Isn't Xen dead? by zaphirplane · · Score: 1

      it was owned by xensource, now owned by citrix, really unlikely that IBM contributed more than the owners.
      Thanks playing FUD and toeing the party line on KVM

    10. Re:Isn't Xen dead? by isopropanol · · Score: 1

      Also, I'd like to point out one stupid thing: VirtualBox won't let you allocate more than half of your physical memory to VMs. Even if you built the machine with excess of RAM so you could do just that... Want to run 2 1GB VMs in a 4GB machine with integrated (RAM stealing) video? can't do it, even if the machine isn't running anything but VMs.

    11. Re:Isn't Xen dead? by fuzzyfuzzyfungus · · Score: 1

      Is that some kind of architectural limit, or has somebody neglected to remove the "stop the machine from thrashing horribly" heuristics from back when 16GB desktops were science fiction?

    12. Re:Isn't Xen dead? by pthreadunixman · · Score: 1

      You have heard of Amazon EC2 right?

    13. Re:Isn't Xen dead? by GPLHost-Thomas · · Score: 1

      Maybe because it's the greatest virtualization technology for servers (see AWS, Openstack, and so on)? Because it's the virtualization of choice for cloud computing, with live migration working like a charm? Or because KVM doesn't offer the kind of functionality one may need, like being able to mount a partition directly in dom0 when you use LVM, and such kind of thing? Because it has great CPU schedulers, and lots of new things for nested virtualization which other products don't have? Or is it because other big companies like Oracle, Intel, Samsung, Fujitsu, or Citrix are working hard with a lot of staff on it? Maybe it's because Xen developers have new Intel hardware before they are out, and could develop things like SRV-IO support before everyone? Take your pick!

      By the way, I wonder why you are saying that the pace of Xen development is pathetic. Have a look at the xen-devel list, and see how many patches are sent to the list every day, or read LKML, or see the latest Xen patches upstreamed to kernel.org kernels during the current 2.6.39 merge window, and you might change your mind.

      Xen isn't great for desktop, but for servers, there's nothing like it, lots of people know it, and contribute to it.

    14. Re:Isn't Xen dead? by GPLHost-Thomas · · Score: 1

      But isn't a contributor.

    15. Re:Isn't Xen dead? by isopropanol · · Score: 1

      I suspect it's neglect.

    16. Re:Isn't Xen dead? by styrotech · · Score: 1

      You must've stopped looking a while ago. Admittedly it looked very grim a couple of years back when KVM hit the big time and Xen was stuck with their aging fork of 2.6.18 and not getting on well with the Linux kernel team.

      But it's different now - the last year or so seems to have been the busiest I've ever seen the Xen devel list and the pace still seems to be increasing. And I've been following along since 2.x or so about 6 or 7 years ago. Additionally the relationship with the Linux kernel upstream seems much improved now too.

      Most of the big or well known "cloud" or virtual Linux server providers still seem to use Xen - eg EC2, Rackspace cloud, Softlayers cloud, Linode, Slicehost, Rimuhosting etc.

    17. Re:Isn't Xen dead? by martyros · · Score: 1

      Ref please? IBM has never been a major contributor to Xen, and Xen development, especially over the last year, has been just fine.

      The project is still alive because it is useful to thousands of organizations (including large corporations like Tesco, Bechtel, Fujitsu, SAP, cloud providers like Amazon and Rackspace, to name just a very few), and thus worth the time of various organizations (including Citrix, Oracle, AMD, Intel, and yes even RedHat) to pay developers to work on improving it.

      Are any major corporations with a significant deployment of KVM or VirtualBox?

      --

      TCP: Why the Internet is full of SYN.

    18. Re:Isn't Xen dead? by martyros · · Score: 1

      I've seen no technical reasons to use it over KVM or VMWare in the enterprise.

      Is anyone using KVM for server consolidation?

      KVM is a great tool for having a secondary VM on your desktop. In fact, one of the Xen developers who works remotely (and thus doesn't have the same access to a big farm of test hardware) actually uses KVM to do Xen development, when what he's working on doesn't require any hardware virtualization features. But if what you want is a dedicated VM-hosting box, Xen is the way to go.

      --

      TCP: Why the Internet is full of SYN.

    19. Re:Isn't Xen dead? by h4rr4r · · Score: 1

      Lots of people do. KVM is what RHEL uses and pretty much everyone else as well. Xen is dead.

    20. Re:Isn't Xen dead? by martyros · · Score: 1

      Ah, that was your prime opportunity to bring in actual examples. The lack thereof makes it clear to everyone that "Xen is dead" is just FUD.

      --

      TCP: Why the Internet is full of SYN.

    21. Re:Isn't Xen dead? by g00ey · · Score: 1

      Something, I'm really missing is a stronger "passthrough" implementation than Intel VT-d/AMD IOMMU that allows any hardware to be passed through to a guest OS / domU such that I can use Unix/Linux as Dom0 and play fully-fledged DirectX11 games on a multiway SLI/CrossFire on a Windows guest machine.

      I have the dream or vision that operating systems will grow into more simplistic hypervisors in the future. System environments that provide APIs such as .net or DirectX will shrink into wrappers that will provide whatever specific resources that are requested by the program to be run. So if you run a MacOS program the wrapper will parse runtime libraries based on the MacOS frameworks to the program whereas a Windows program will use Windows runtime libraries through this wrapper and so on.

      So there will be a separation between the hardware and the operating systems by an abstraction layer where different wrappers (that used to be operating systems) share the underlying hardware with each other. There will no longer be a question whether you use Windows, MacOS or Linux. You just use whatever you prefer as a base OS and use whatever is needed to run the applications you want, which in reality could mean that you run several operating systems simultaneously on the very same machine.

      This separation has already begun, ZFS is a good example of that. The ZFS file system looks at the hard drives as a storage pool and the user is not concerned with the physical characteristics of the partitions and where the sectors begin or end. I didn't like it at first but later found that this approach is ingenious. So I see it as a natural step that the rest of the hardware will undergo the same transition. I also think a lot can be done with the UEFI framework in this regard.

    22. Re:Isn't Xen dead? by pasikarkkainen · · Score: 1

      Actually Xen is far from dead. Development is very active, and most of the important kernel-related patches have been upstreamed and included to Linux, including the much discussed Xen Dom0 support. So the situation nowadays is very different from a couple of years back.

    23. Re:Isn't Xen dead? by pasikarkkainen · · Score: 1

      Great post! Many people don't seem to realize a lot has changed in the Xen-land during the last couple of years.. Xen dom0 support is now included in the upstream Linux kernel, and Xen developers are at the moment actively working on upstreaming for example qemu-xen to upstream Qemu. And for people who don't want to "do-it-yourself" there's Xen Cloud Platform (XCP) available.. opensource dedicated virtualization platform shipped as installable ISO image. http://xen.org/products/cloudxen.html .

  3. Sorry, I have another negative xen comment. by chickenrob · · Score: 1

    I run openSuse 11.2 which includes integrated support for hypervisor. When I attempted to implement it it required a kernel adjustment of some sort and a reboot. When I rebooted there was some issue with my screen configuration and x would not start up. I gave up and installed virtualbox instead which is freaking rad and worked flawlessly. Is there an advantage to xen that makes it worth the hassle?

    --
    People say my sig is the best thing about me.
    1. Re:Sorry, I have another negative xen comment. by Anonymous Coward · · Score: 0

      apple meet orange. One is for desktops and one is for servers.

    2. Re:Sorry, I have another negative xen comment. by Anonymous Coward · · Score: 0

      You visibly have no idea what Xen is and you were trying to use it for the wrong purpose.

      VirtualBox is what you need.

    3. Re:Sorry, I have another negative xen comment. by theillien · · Score: 1

      I disagree. I've successfully used Xen on a workstation. As long as the processor supports virtualization and has the capacity and there is enough RAM to run more than one VM smoothly it is irrelevant whether the hardware is a desktop or a server. If the OP had hassles, I'd wager he simply didn't have a powerful enough machine regardless of the platform.

    4. Re:Sorry, I have another negative xen comment. by Rennt · · Score: 1

      Xen isn't really for designed for desktops or workstations - VirtualBox's ease of use and integration extensions make it a clear winner in that area.

      But Xen is at home in datacenters/blade clusters/VPS hosting where kicks VMWare's ass.

    5. Re:Sorry, I have another negative xen comment. by Anonymous Coward · · Score: 0

      Xen is a type 1 hypervisor and virtualbox uses emulation. Big thing you will notice is between 2-4% overhead for Xen and up to 30% for virtualbox.

      It really depends what you are after, I use XenServer most of the time at home/work but on the road I fall back to Hyper-V on my laptop

    6. Re:Sorry, I have another negative xen comment. by GPLHost-Thomas · · Score: 1

      Xen isn't a product for your desktop, on that side, it is both hard to use, and a pain. It integrates badly with DHCP, and almost never works with a WiFi card. That isn't why we love Xen. We love it on the server side. For your desktop, you did the right move when using Virtualbox.

    7. Re:Sorry, I have another negative xen comment. by RocketRabbit · · Score: 1

      How's that? Did you hear it somewhere or can you prove it?

  4. Will Citrix take notice by theillien · · Score: 1

    XenServer, despite being pretty much the same product, is crap. Somehow, Citrix managed to ruin something that, at the time they bought it, ran well and was fairly solid. They changed enough to make it kludgy pile.

    1. Re:Will Citrix take notice by vux984 · · Score: 1

      So what is the best solution out there right now?

      I've got some vmware server stuff at home, and some Xen stuff at work, I wasn't happy with some of the vmware is doing, and if Xen is going down the crapper too...

      What is decent and getting better?

    2. Re:Will Citrix take notice by theillien · · Score: 1

      KVM seems to be the Next Big Thing. I don't have much experience with it. The last time I tried to get it up and running on a workstation using CentOS 5.something it failed miserably. I couldn't even get it running. It has reached much better maturity now, though. At least, I'm putting my faith in that statement seeing as Red Hat has phased Xen out and is moving all of their VM eggs into the KVM basket. I've been meaning to try it out again and see what I can do. I've heard anecdotal evidence that it is far more efficient since it is hooked directly into the kernel.

    3. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      VMWare is a solid pay-for product with support and an ecosystem. Xen is a fast, free, open alternative, with a few years of enterprise deployments under the belt now. KVM is good technology and should be ready for the enterprise in about 3-4 years... ...by which time "something else" will be the newest, coolest, cleverest project in the space. When will people learn that their employer values stability and efficiency in IT, along with an ability to support the scaling of their business without significant additional costs?

    4. Re:Will Citrix take notice by drsmithy · · Score: 1

      So what is the best solution out there right now?

      VMware. Nothing else comes close.

      It *is* expensive if you want all the cool stuff, though.

    5. Re:Will Citrix take notice by DCFusor · · Score: 1

      I know another guy who used to say that. I showed him VB (free) and he was amazed by it. Maybe you should check it out.

      --
      Why guess when you can know? Measure!
    6. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      The specific "something" matters -- RHEL5 did a massive upgrade from an antique build of KVM to a merely old one fairly late in its lifecycle. Even then, it's a backport to a very old kernel; the RHEL6 series KVM is far more modern.

    7. Re:Will Citrix take notice by drsmithy · · Score: 2

      I know another guy who used to say that. I showed him VB (free) and he was amazed by it. Maybe you should check it out.

      I assume you mean VirtualBox. Virtualbox is an OS-hosted end user virtualisation application. It's not even playing the same game as bare metal hypervisors like and Xen and VMware ESX.

    8. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      Really? Try Marathon MX. Can you turn off a VMware server and have it failover without dropping a ping or skipping a beat? It's not the easiest to maintain, with having to use the XenServer and Marathon consoles for various things, but it's solid. I've installed the Marathon FT, 2G and now MX servers in casinos around the world - handling patron card and electronic ticketing. Wouldn't do a new install without it.

    9. Re:Will Citrix take notice by SilentChasm · · Score: 1

      How do you do a server with virtual box, preferably with a minimum of command line (I like GUIs, even text based ones)?

      I tried virtual box and even used it for my mom's virtual machine so she could run her old windows programs (before VMware player could make VMs) and it worked nicely for that, but it never seemed to be server oriented for what I wanted to do (mail/dns/file servers).

      One thing I've never got working on VMware or Virtual Box on any version or platform is USB support. I must be doing something wrong.

    10. Re:Will Citrix take notice by drsmithy · · Score: 1

      Can you turn off a VMware server and have it failover without dropping a ping or skipping a beat?

      Yes, though such a capability is just an ugly kludge for broken applications without native fault tolerance.

      A better solution is to (re-) design the software so it can handle failures on its own. That way you can be protected from software errors as well as hardware ones.

    11. Re:Will Citrix take notice by Bios_Hakr · · Score: 1

      I recently attended a conference hosted by VMWare. I spent a bit of time talking geek with one of the tech guys. Mostly we talked about vSphere's new *virtual* cisco switches. Anyway, the engineer said they have some support for some USB devices.

      That being said, I have never gotten USB to work in VB or VM Ware...

      --
      I'd rather you do it wrong, than for me to have to do it at all.
    12. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      "How do you do a server with virtual box, preferably with a minimum of command line (I like GUIs, even text based ones)?"

      Then I'm afraid you don't know what you are talking about. "Server" relates to "automation", not "interactive". "GUI" and "automation" are completly opposites, therefore "server" and "GUI" means "I don't know what 'server' really means".

    13. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      vbox has an extensive cli interface, and very good documentation, i thought. i am a macfag now and use parallels for all my virtualization but back when i was 100% linux i was a big vbox fan and it was the best desktop vm host out there by far.

    14. Re:Will Citrix take notice by secolactico · · Score: 1

      A better solution is to (re-) design the software so it can handle failures on its own. That way you can be protected from software errors as well as hardware ones.

      As much as I agree with that sentiment, I'll be among the first to admit that that's unlikely to happen in a reasonable time-frame in a less than perfect world.

      Ugly kludge solutions will always have a place in the industry because of this.

      --
      No sig
    15. Re:Will Citrix take notice by larppaxyz · · Score: 1

      What makes XenServer crap? I think it's great, even the free version.

    16. Re:Will Citrix take notice by martyros · · Score: 1

      I don't know what GP was talking about wrt XenServer. XenServer is a great piece of software, and getting better all the time; the free-as-in-beer version is very fully featured, missing only high-end features like automatic fail-over and disaster recovery. You can still create pools of VMs using shared storage, and there are no limits on the number of VMs, amount of memory, amount of virtual cpus, or anything like that. And if you prefer an "open" distribution, you can use the Xen Cloud Project, which is very similar to XenServer, but designed to be community-developed (and thus completely free-as-in-speech as well).

      As a developer who joined XenSource and now works for Citrix, I have to say they did a really good job of not screwing up the acquisition. Even though all of the XenSource options vested some time ago, a large percentage of the core developers still work for Citrix, and show no signs of leaving any time soon. So the "Big corp bought something cool and screwed it up" narrative just doesn't fit here.

      --

      TCP: Why the Internet is full of SYN.

    17. Re:Will Citrix take notice by Anonymous Coward · · Score: 0

      ESX/i 4.1 does USB nicely. You can even vMotion a VM with the USB device connected.

    18. Re:Will Citrix take notice by h4rr4r · · Score: 1

      How do you do a server with virtual box, preferably with a minimum of command line
      You don't belong near a server.

    19. Re:Will Citrix take notice by DarkOx · · Score: 1

      By cool stuff... the parent poster was likely talking about things like VMotion, DRS, hotsite replication and other stuff.

      Post back when Virtual Box can migrate a VM from one host to another hot without even dropping my SSH session.

      --
      Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
    20. Re:Will Citrix take notice by theillien · · Score: 1

      I find the free version to be better than the Citrix version. The problem I have with the Citrix version is that they took Xen and tried to reshape it into a VMware clone right down to the GUI used to manage it. In the process, they changed how things are managed on the command line and left holes in not only the documentation of those changes but also the functionality in the overall product. I think Citrix buying Xen was a step backward and if Xen had not been bought it probably would have advanced further than it has and been a better product than it turned out to be.

    21. Re:Will Citrix take notice by Jumpy · · Score: 1

      I've recently started using KVM as a desktop virtualization solution. On CentOS 5.5 and RHEL 6.0 Its pretty damn awesome imho. You can use virt-v2v to convert older VMs to newer VMs. Also can convert VMware VMs though I have not done that. I am using KVM to lean more about different Linux distros besides Red Hat. I have 4 VM's always running on my desktop at work (RHEL 6) as test boxes and I don't notice that much of a slowdown. I give a huge thumbs up to KVM. I have to use VMware at work but KVM is a better Linux solution for me. No rdesktop to a stupid windows box to run viclient for 1 example.

      Sometimes I have had to change network from virtio to E1000 for some Linux flavors to get network to work but in general it just "works." I never got into Xen though. I gather the commands are similar. (virsh start domainname, virt-manager, etc.)

      --
      -- If there's one thing i can't stand, it's intolerance!
  5. Oblig. XKCD by Wingman+5 · · Score: 1

    Obligatory XKCD

    1. Re:Oblig. XKCD by Terrasque · · Score: 1

      So, let me get this straight..

      You suggest that everyone should stop their work on anything that can be linked to linux in any way, until Adobe fixes their piece of crap?

      --
      It's The Golden Rule: "He who has the gold makes the rules."
  6. Too much FUD. by PiSkyHi · · Score: 2
    14 Comments so far and no one seems to have read the Xen 4.1 wiki. Just to clarify, Xen and KVM are similar and you can use them for similar purposes. Xen 4.1 is aiming to be integrated into the native Kernel, it is very close already having some dom0 support now, native guest support as of 2.6.36 and will have full dom0 support soon. dom0 and domu kernels are now de-coupled, so things are going to become more generic which distributions will love.

    I tried and failed at Xen 4.0 after using Xen 3.x successfully sometime beforehand - I have been waiting for all those involved to update, stabilise and simplify Xen - looks like it is coming very soon.

    Redhat not using Xen for sometime now, fair enough, I'm not using Redhat so it won't bother me much.

    1. Re:Too much FUD. by Anonymous Coward · · Score: 0

      Perhaps Xen will one day work on FreeBSD as Dom 0 - its the only kernel worth integrating with.

    2. Re:Too much FUD. by timbo234 · · Score: 1

      Xen 4.1 is aiming to be integrated into the native Kernel, it is very close already having some dom0 support now, native guest support as of 2.6.36 and will have full dom0 support soon

      This is the crux of the matter, Xen has been going into the mainline kernel 'any day now' for the past 3 or 4 years. It's hard to believe that it took them until 2.6.36 (October 2010) to even get the domU support in there. Either Xen development proceeds at a snail's pace or the project is run by people who don't want to fit into the guidelines for code submitted to the kernel. Either way I can only see KVM running ahead in leaps and bounds while Xen struggles with getting into the kernel, and people struggle to get Xen installed.

      Your right that Redhat has gone away from Xen, although it was only last month with the release of RHEL6, their first version without official Xen support. Novell's keeping up Xen probably mainly for competitive reasons - to have a differentiated product from Redhat, but it also fully supports KVM: http://www.h-online.com/open/news/item/Novell-supports-KVM-963031.html

      --
      Pre-canned Evolution Links for all those Slashdot holy wars.
    3. Re:Too much FUD. by Eil · · Score: 1

      It's hard to believe that it took them until 2.6.36 (October 2010) to even get the domU support in there. Either Xen development proceeds at a snail's pace or the project is run by people who don't want to fit into the guidelines for code submitted to the kernel. Either way I can only see KVM running ahead in leaps and bounds while Xen struggles with getting into the kernel, and people struggle to get Xen installed.

      Xen was originally not accepted into the kernel because it was basically delivered as a huge monolithic patch that touched too many different parts of the kernel and had an external dependency as well. (The hypervisor.) KVM came along, promised to do the same thing with much less code and without external dependencies and was accepted into the mainline kernel before it was really even all that stable.

      From what I'm lead to understand there are still prominent mainline kernel developers who believe that there is no good reason to have two functionally similar (but completely independent and incompatible) virtualization systems in the kernel.

    4. Re:Too much FUD. by ijc · · Score: 1

      IIRC Xen 32 bit PV domU support was origianally added to mainline in the 2.6.22 or 23 release and 64 bit support was added in 2.6.27.The "native guest support as of 2.6.36" referred to in the parent was the addition of PV driver support (e.g. for disk and network devices) when running in a fully virtualised (AKA HVM) guest. Fully virtualised guests worked fine before then but with emulated devices.

    5. Re:Too much FUD. by Anonymous Coward · · Score: 0

      It does work with NetBSD as dom0

  7. Xen is great on servers (not so much desktop) by KillNateD · · Score: 1

    If you want to run a ton of VMs on a server, Xen is great. It's fast and stable once you sort through the mess of getting a kernel that both supports your hardware and runs well as a Dom0 (the "host" machine).

    And for the past year or two, most distros have shipped kernels which would boot just fine "out of the box" on Xen virtual machines.

    It's what most "cloud" or VPS providers run (including Amazon, Rackspace, Slicehost, Linode, etc).

    However, if you're running a desktop and want to virtualize, Xen is probably going to be a HUGE pain in the balls, with no real benefits. Just use KVM or VirtualBox.

  8. It's the manageability and feature understanding by jimicus · · Score: 1

    Yeah, so Xen has all these fancy features. So does KVM. So does VirtualBox. So does VMWare.

    The underlying features aren't really the important point - they haven't been for some time and that isn't going to change with this release. The important features right now are manageability - is there a pretty GUI to show the managers? A programmable, easily scriptable API? - and full feature-parity with the likes of VMWare. (Doesn't have to be parity with the enterprise versions, just parity with the free VMWare server will do).

    And by feature parity I do not mean "feature parity in theory but it doesn't work in practise because we worked it out by looking at the names of all the features, guessing what they meant and replicated them. Further investigation shows our guesses were wrong in a few places, but hey..."

  9. So, still doesn't alllow online resize of disks by Eunuchswear · · Score: 1

    Bummer.

    --
    Watch this Heartland Institute video
    1. Re:So, still doesn't alllow online resize of disks by Anonymous Coward · · Score: 0

      What disks are you referring to? A guest's root disk can't be resized on the fly, but you can resize a guest's data disks if they're using Linux and LVM. You could do this in Xen 3 as well.

      From host (expand 1GB):
      dd if=/dev/zero bs=1M count=1024 >> guest.disk.img

      In guest:
      hdparm -z /dev/xvda2 (or whatever the device is)
      pvresize /dev/xvda2
      lvresize -L +1G /dev/vgname/lvname
      resize2fs /dev/vgname/lvname

    2. Re:So, still doesn't alllow online resize of disks by pasikarkkainen · · Score: 1

      Xen online resizing of VM disks has been supported for a while already! You just need to use a kernel that supports it. Online resizing is supported in mainline upstream Linux as of 2.6.37 (iirc), and some distros have backported it older kernels.

    3. Re:So, still doesn't alllow online resize of disks by Eunuchswear · · Score: 1

      So, what's the XM command to tell the guest that the disk size has changed?

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    4. Re:So, still doesn't alllow online resize of disks by pasikarkkainen · · Score: 1

      No need to run XM commands, it's enough to resize the LVM volume in dom0, and domU will pick up the change automatically (assuming both dom0 and domU kernels have the online resize feature included).

    5. Re:So, still doesn't alllow online resize of disks by Eunuchswear · · Score: 1

      Is this written down anywhere? I've been looking all over the place and all I can find is that there used to be a xm command to do it but it was removed.

      All I can find is discussion of resizing volumes offline. I want to resize a volume without restarting the domU.

      --
      Watch this Heartland Institute video
    6. Re:So, still doesn't alllow online resize of disks by Eunuchswear · · Score: 1

      Aha, at http://wiki.xensource.com/xenwiki/XenParavirtOps I find:

      Features added in 2.6.36:
      Xen VBD (Virtual Block Device) online dynamic resize support for resizing guest disks (xvd*) on-the-fly.

      --
      Watch this Heartland Institute video
    7. Re:So, still doesn't alllow online resize of disks by pasikarkkainen · · Score: 1

      It's mentioned on the Xen4.0 wiki page since that's when the feature was developed. http://wiki.xen.org/xenwiki/Xen4.0 . I think it was originally submitted by Novell developers, who wrote it for SLES11. Later Jeremy (pvops kernel maintainer) submitted it for upstream kernel inclusion, and it got included to upstream Linux in 2.6.36. It's also included in xen.git xen/stable-2.6.32.x branch. I've tested it myself, and all you need to do is to resize the LVM volume in dom0, and domU will detect the size change.

  10. Hyper-V by cyber-vandal · · Score: 1

    Does anyone actually use this?

    1. Re:Hyper-V by Anonymous Coward · · Score: 0

      Does anyone actually use this?

      some nearly unknown company you may not yet have had the displeasure of dealing with, i think they are called micro soft?

    2. Re:Hyper-V by Anonymous Coward · · Score: 0

      Hyper... what now? Arhh thats right, Microsoft's Xen for Windows. Sorry no one uses it.

    3. Re:Hyper-V by sirsnork · · Score: 1

      Plenty of people, but mentioning it here is probably risky.

      If you're running predominatly Windows servers, it's the only way to go unless you want some of VMWares really advanced features, even then it's catching VMWare slowly.

      Personally I run ESXi at home since my home server doesn't have VT, and HV at work in a 6 node cluster.

      --

      Normal people worry me!
    4. Re:Hyper-V by Anonymous Coward · · Score: 0

      Hyper-v only supports Windows and RHEL/SUSE. For companies running only windows it might be an option, but for the rest of the world XEN makes alot more sense. Ask yourself this simple question: would you trust Microsoft to hypervise your quests? (weee.... internet explorer has been updated with random patch. restart your computer now or in 15 minutes?)

    5. Re:Hyper-V by gollito · · Score: 1

      Hyper-V is just.....wrong. Feature wise (and maybe just in in how the features are implemented) it doesn't compare to vmware. Take networking for example. In vmware it's easy as pie to setup VLAN's, VM only networks, etc. In Hyper-V it's a somewhat complicated process. The thin provisioning of hard drives by default is bad, bad, bad. Give me the option during VM build like vmware does.

  11. Hypervisor != HUD goggles? by Saint+Ego · · Score: 1

    I was sorta hoping this was about a new Vuzix competitor...

    --
    Reality is prettier inside my head...
  12. Is Xen really a has been? by Anonymous Coward · · Score: 0

    I'm surprised only negative comments have been posted so far. In the free/OSS type 1 (bare-metal) hypervisor space, is Xen really that far behind? I guess I need to branch out more. I've been running Xen 3.2 for a while and been pretty happy with it. It's a giant pain to install but after that it's okay.

    I know vmware stuff is pretty good but I have to pay money for that. Hyper-V requires Windows so that costs money as well. (I'm poor.) To those who would say I should try virtualbox, I have and it's good but it's a type 2 hypervisor and it's not really what I'm looking for to do server virtualization. I guess I better try KVM again. Last time I tried KVM it still needed to mature some more. Sounds like people love it now.

  13. Re:It's the manageability and feature understandin by Anonymous Coward · · Score: 0

    You mean something like libvirt and derivatives?

  14. Re:It's the manageability and feature understandin by keith_nt4 · · Score: 1

    I've been working for weeks toward setting up a test box for Xen (I want to learn it for work). In my research i found the webmin-related product cloudmin which works for both Xen and KVM. Haven't tried it yet, hopefully it's as good as regularly webmin. That'd provide the GUI, not sure about the other stuff.

    --
    "UNIX is very simple, it just needs a genius to understand its simplicity." -Dennis Ritchie
  15. Anyone still use it by Billly+Gates · · Score: 1

    Just curious

    --
    http://saveie6.com/
    1. Re:Anyone still use it by Anonymous Coward · · Score: 0

      I'd say... EC2?

    2. Re:Anyone still use it by Anonymous Coward · · Score: 0

      Yes, because it is the only alternative to Vmware on the servers.

    3. Re:Anyone still use it by gpuk · · Score: 1

      Linode

  16. Re:It's the manageability and feature understandin by GPLHost-Thomas · · Score: 1

    Maybe you should give a go to our DTC and DTC-Xen then? Both are included in Debian and Ubuntu ... Thomas

  17. Xen is alive and well by derinax · · Score: 1

    Don't believe the FUD in these party-line comments. I run a NetBSD Dom0 with now 7 Red Hat DomU's in an LDAP/messaging cluster on a single server, scoped to 10 concurrent VMs hitting iSCSI cluster targets.

    It's not a desktop product. It's designed for high-availability and dense clustering, has a mature codebase and tools, and it works well. And yes, Red Hat 6 runs just fine as a DomU out of the box, and can be a Dom0 as well, if you like (although not "supported" by Red Hat, still quite functional).

  18. Re:Stop hating by Democritus+the+Minor · · Score: 1

    Xen is good. KVM won't run on my intel atom boards anyway... No point in expecting all cpus to support hardware virtualization.

    HVM is slower than Paravirtualization anyway... as a rule.

  19. And you're wrong by Anonymous Coward · · Score: 0

    Xen is nothing like KVM. KVM is integrated into the normal linux kernel and can run any OS you ask it too using HW virt,

    Xen can use full-virt too with hw-acceleration, but it still needs you to run a separate hypervisor, and a daemon in your dom0.
    Xen paravirt is even worse, requiring you to run a patched kernel in your domU as well, severely limiting your options as too what OS you can run.

    tl;dr
    KVM is nice, Xen sucks

  20. XEN kicks ass by Anonymous Coward · · Score: 0

    I seriously have no idea why RedHat went on with KVM. KVM does not even support live migration. And Redhat is supposed to be the THE enterprise linux. Also, in the world of virtualization it might be important (hint: some anal software vendors still sometimes rely on hardware dongles. which only cause pain to paying customers such as myself) to have a possibility to bypass USB. Try that sometimes. It turns out to be quite an adventure. Last time I tried that I ended up paying quite a sum to VMWare. I tried very hard not to do that.

    1. Re:XEN kicks ass by h4rr4r · · Score: 1

      KVM has done live migration for ages now. Passing usb in kvm is quite easy, heck you can do it with qemu commands if you want.

      Sounds like you are out of touch with reality.

  21. Re:It's the manageability and feature understandin by martyros · · Score: 1

    The underlying features aren't really the important point - they haven't been for some time and that isn't going to change with this release. The important features right now are manageability - is there a pretty GUI to show the managers? A programmable, easily scriptable API?

    Consider the Linux kernel from the criticisms you've just made. Does Linus's tree have important features for manageability? Does it have a pretty GUI to show managers? Is it programmable and easily scriptable? The answer is, of course, no; management, GUI, scripts & come from other projects built on top of the Linux Kernel.

    The same is true of Xen. The core Xen project is about operating-system-level functionality, just like Linux is. It is, if you will the engine; but what most people want is a car. The scriptable engines, GUI, management tools, and so on are of a completely different type of programming than OS programming, and should be separate projects.

    And these projects exist. XenServer is such a system that includes everything that you describe; and the free-as-in-beer version is very powerful. For those wanting an open system, the Xen Cloud Project is a community-oriented version with feature parity, having been based on the same codebase. Additionally, there are people working on porting libvirt bindings to Xen 4.1, so that any management and GUI software that uses libvirt as a backend to manage KVM can also manage Xen.

    --

    TCP: Why the Internet is full of SYN.

  22. Desktop color depth by NitroWolf · · Score: 1

    But does it finally support 24 and 32 bit color depth on the desktop? That was a huge stopping/stumbling block for me on integrating Zen into our datacenter. We ended up going with VMWare's ESXi because it's the only hypervisor that supports 24 bit color depth that I found. I would really have preferred Xen but they seem to have completely ignored the video memory segment of their product.

    Anyone know why this is? It seems like it would be a simple addition.

    1. Re:Desktop color depth by pasikarkkainen · · Score: 1

      truecolor framebuffers have been supported for many years in Xen. You can install either PV or HVM VMs using truecolor graphics. In the case of PV domU you need to use 'vfb' or 'pvfb', aka paravirtual framebuffer. Framebuffers are exposed as VNC servers, or over SDL.

  23. The top 4 IaaS Cloud Providers do by Anonymous Coward · · Score: 0

    Since 2009 Jack of All Clouds has been putting together a survey of who the largest cloud providers are, using public data from Quantcast to figure out which of the top 500K website are powered by which cloud provider und use that data to rank those providers (and they publish the top 6 or 7 almost every month). See the January report as an example.

    The top providers are Amazon (Xen), Rackspace (Xen), Linode (Xen), GoGrid (Xen), Joyent (KVM) and OpSource (ESX). Obviously the published data will miss many of the smaller vendors, but it is striking that the top 4 vendors use Xen.

  24. Re:It's the manageability and feature understandin by Anonymous Coward · · Score: 0

    The important features right now are manageability - is there a pretty GUI to show the managers? A programmable, easily scriptable API?

    There is a sa lighweight API called LIBXENLIGHT with a toolstack called XL. If you are looking for a GUI manager the way to go is to use XCP which includes a more powerful toolstack. XCP 1.0 has not caught up with Xen 4.1 yet,but the next release is planned to as far as I know. In any case, there are lots of management tools forXCP which you can pick from. See XCP_Projects

  25. Xen dom0 support IS in mainline Linux by pasikarkkainen · · Score: 1

    Actually Xen dom0 support *IS* already in mainline upstream Linux kernel as of 2.6.37 ! Some xen backend drivers are still missing from upstream kernel, but upcoming Linux 2.6.39 includes xen-netback backend driver, and xen-blkback driver is planned for 2.6.40. http://blog.xen.org/index.php/2011/01/14/linux-2-6-37-first-upstream-linux-kernel-to-work-as-dom0/ The pvops framework was merged to Linux 2.6.24 a couple of years ago, and Xen pvops domU support was first usable in Linux 2.6.26. So Xen support has been in upstream Linux kernel for 12 major kernel releases already! Also Redhat RHEL6 runs as Xen VM, both PV and HVM, just as pretty much any distro does nowadays. Upcoming Fedora 15 has a Xen dom0 capable kernel, and it is expected that Fedora 16 will have fully featured Xen dom0 support out-of-the-box (including all the backend drivers that are being upstreamed atm).

    1. Re:Xen dom0 support IS in mainline Linux by timbo234 · · Score: 1

      So some time early-mid 2012 we can expect to see proper dom0 support in the kernel, ie. you won't need a specially patched kernel to run a Xen server as you do today (even with 2.6.37)? This is good but still about 5 years after KVM entered the mainline kernel.

      --
      Pre-canned Evolution Links for all those Slashdot holy wars.
    2. Re:Xen dom0 support IS in mainline Linux by pasikarkkainen · · Score: 1

      If you're using Xen 4.1.0 then 2.6.39-rc1 or newer as dom0 kernel will allow you to run VMs, since 2.6.39 includes xen-netback backend driver, and Xen 4.1 includes userspace/qemu-based blkback backend implementation. There's ongoing process to upstream the remaining bits.. based on earlier experiences upstreaming all at once clearly doesn't work, so it has to be done in small incremental steps :) Meanwhile there is 2.6.32 based long-term maintained tree with full dom0 support included available in xen.git in xen/stable-2.6.32.x branch.