Qemu-kvm Package?

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I just did a clean net install of CentOS 6.4 and when I run virt-manager it says that qemukvm is missing, but when I try to install it with yum it says that there isn’t a package with that name. Is something wrong with my configuration? Or what is causing this package to appear as not available?
Thanks, Dave

19 thoughts on - Qemu-kvm Package?

  • From: Dave Johansen

    Google told me:
    “Whilst previous versions of RHEL supported KVM on both 32-bit and 64-bit systems, as of RHEL 5.4 support for KVM virtualization is only available for 64-bit (x86_64 architecture) versions of the operating system.”
    But I never played with it so I cannot confirm…


  • Really? Is there a reason why that is the case? Because the hardware supports it and so is it just that the software doesn’t support
    32-bit? That’s kind of surprising because my experience has usually been that if both weren’t supported then it was 64 bit that was lacking.

  • Nowadays you should always install 64 bit. 32 bit is a legacy architecture and should not be used unless you absolutely have no other choice.


  • Unfortunately, for me that is the case. The laptop I was doing this on
    (Thinkpad T60) doesn’t support x64.

    But the “32 bit is legacy” argument seems a bit odd and that’s the first time I’ve heard that. Maybe I’m just a bit out of that loop, but the reason I say that is that before doing this install, I had Fedora
    19 on the machine and kvm worked just fine on the machine, so if it really was that “32 bit” wasn’t being supported for things like kvm anymore, then why does a “cutting edge” system like Fedora 19 have support for it?

  • I’ll really like CentOS/RHEL and will definitely stick with it. The point of my questions wasn’t to complain or any like that, but just surprise because it seemed that the no 32 bit support didn’t line up with my experience and just trying to make sure I understood everything.

    Thanks, Dave

  • I suspect that with the notion of modern OSes normally needing at least
    1G each even in a VM (often much more), the choice was to steer resources to the 64bit platform for virtulization because 32bit machines can’t address nearly as much memory space, often a key factor for VMs.

    given the amount of resources to maintain a platform that can’t really support production workloads and most modern machines should be able to switch to 64bit OS pretty seamlessly, I suspect there was no justification to keep support for a 32bit version.

    just my theory, not sure if it’s of any help for you.

  • Virtualbox isn’t ‘instead of’ CentOS’ it is ‘instead of KVM’ as a virtualization layer. Not sure how much difference there is in capability, other than being available for many more platforms, including 32-bit linux. There should be some overlap in supported image formats. I’ve moved vmdk’s created on vmware to both, but I’m not sure what others they each handle.

    If you have hardware support for virtualization, you should probably be running 64-bit CentOS with KVM and not much else at the host OS
    level. If you have applications that need 32-bit, they could run in a guest.

  • The important thing here is the different possible meanings of the word
    “support”. Fedora doesn’t support things in the same way RHEL/CentOS
    does. In Fedora “supports X” means “is technically capable of doing X”
    however in enterprise distros support actually means that the company guarantees (within limits) that X works and if it doesn’t work for a customer it expends engineering resources to fix whatever the problem is.

    In the case of 32bit vs 64bit KVM Red Hat simply decided that it doesn’t want to incur all the trouble/costs it would take to actually name 32bit KVM as supported since 98% of the systems KVM will be used on nowadays are 64bit capable.

    Since Fedora does have to deal with these issues only on a “we’ll try to keep things working but if we fail you are on your own” basis they probably have no reason to disable 32bit support.

    My guess is that if you flip a few switches in the source kernel and qemu/kvm packages to compile in the 32bit modules you should be able to make it work but I haven’t dealt with a 32bit system in years so I’m not sure if this is enough to get things going.


  • Yes, that is exactly what I meant. If you want ot keep running 32-bit CentOS and have Virtualized guest, VirtualBox is excellent choice. Same image can be run on both Linux and Windows host systems,

    CentOS is multiarch, all libraries/packages necessary to run any 32-bit app exist on 64-bit system, so it can be run on 64-host, no need to have guest for that.

  • The issue is that I have two machines and one has hardware support for virtualization but doesn’t support x64, and the other is flipped. So I
    was hoping to be able to it on the 32-bit machine to get the speed up from hardware support, but I guess I’ll just do it on the 64-bit machine and pay the price of emulation.

    The reason I want to use virtualization is not on a big server, but just as a way to test builds/software on different OS versions for submission to the EPEL and Fedora. So not everyone in the world is using virtualization for server type stuff, but I realize that is the large majority of the use cases.

  • What processor does hardware virtualization but isn’t 64-bit?

    If you want a 64-bit guest, I think the host has to support both hardware virtualization and 64-bit, although the host OS doesn’t technically have to be a 64-bit version. For example I have run a
    64-bit linux guest under 32-bit windows XP with vmware player – and I
    think virtualbox would do the same..

    Your use case should be fairly common, but you need host support if you want 64-bit guests.

  • Let me say that your question does not match your subject.

    I run a 32-bit CentOS with virt-manager installed to monitor the virtual machines running on a 64-bit CentOS. That leaves the following:

    Is it because I’m running CentOS 5.9 in both cases?
    Or is it because I performed a full install from a DVD in both cases?

    That being said, It’s a fact that virt-manager will run on a 32-bit OS.

    Thanks, Gene Poole

  • No, I think the subject is right. You can install/run virt-manager and use it as a client to 64-bit systems (in 6.x also). But you can’t connect to localhost even though there is a libvirtd because of the missing qemu-kvm package.