KVM In CentOS 5?

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Hi folks,

I’ve been trying to do some KVM virtualization on a C5 host, and to my surprise, there seems to be no kvm package in any of the repos. Yum install kvm says:

No package kvm available. Nothing to do

This machine is a CentOS release 5.10 (Final) with the
2.6.18-371.11.1.el5 kernel.

Also, the docs related to C5 on

http://wiki.CentOS.org/HowTos/KVM

seem to be terribly outdated. What am I missing here?

TIA, :-)
Marko

10 thoughts on - KVM In CentOS 5?

  • I did read those. On page 31 the instructions say that kvm can be installed via yum by saying “yum install kvm”. That’s where I got stuck.

    This host is a remote machine, and I will not have physical access to it until next month. While I do plan to scrap it and install C7, I
    don’t feel like attempting to do that remotely. :-)

    As for guests that should run on that host, I figured that I could create and run them even now, and just back them up when I get to upgrading the host. I wouldn’t like to waste a whole month of guests not running, just waiting for the host upgrade.

    So, is there any possibility to have kvm on C5?

    Best, :-)
    Marko

  • At the bottom of page 15 it specifies that you must be running a
    64-bit OS on (obviously) 64-bit hardware. are you?

  • 2014-08-07 23:21 GMT+03:00 Marko Vojinovic :

    yes, just do ‘yum install kvm’ and remember that x86_64 cpu with hardware virtualization is needed ..

  • Oooh, no. The hardware certainly is 64-bit, and does have the vmx flag. But it turns out that the C5 installed on it is 32-bit… Damn old thing, I completely missed to check for OS arch.

    I guess that explains it, then. Sorry for the noise. :-(

    Thanks, :-)
    Marko

  • … And in addition to that, I need to have a 64-bit OS running on it, which I apparently don’t. Just my luck. :-(

    Best, :-)
    Marko

  • Technically you don’t need to have a 64-bit host OS to virtualize a
    64-bit guest but that may be the way kvm is built. I know I used to run 64-bit linux versions under vmware player on a laptop running
    32-bit windows XP. Maybe virtualbox would work…

  • To the best of my knowledge, vmware emulates generic CPU, therefore, guest can have different architecture from host. Emulates meaning, in particular, what is CPU register for guest is actually sitting in RAM. Therefore, regisetr-to-register operation for vmware guest ias asctually physical RAM to physical RAM operation which is a couple of orders on magnitude slower (well, was long ago, and I’m sure still is). And the same goes about other kinds of CPU command execution of guest OS. This, however is not the case with KVM, portions of guest machine code is run directly in physical CPU, in different privilege ring, of course. (more knowledgeable people will add/correct here).

    Thanks. Valeri

    ++++++++++++++++++++++++++++++++++++++++
    Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247
    ++++++++++++++++++++++++++++++++++++++++

  • I don’t think that makes any sense in the context of CPU’s with hardware virtualization capability – which is necessary for 64-bit guests anyway. And it doesn’t match the speeds I’ve observed for vmware vs kvm guests which seem about the same. It might be true when running 32 bit guests on hosts where the CPU does not have hardware virtualization support.

  • Yes, I should have mentioned that. Vmware changed from emulating CPU to hardware virtualization some time ago. I was referring to older vmware virtualization for which it is possible to have different host and guest architecture. The last was mentioned in post I answered to… Sorry I
    introduced confusion.

    ++++++++++++++++++++++++++++++++++++++++
    Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247
    ++++++++++++++++++++++++++++++++++++++++