[CentOS-virt] KVM: where are the directions?

Thu Nov 11 21:50:11 UTC 2010
Kenni Lund <kenni at kelu.dk>

2010/11/11 MargoAndTodd <margoandtodd at gmail.com>:
> On 11/10/2010 08:31 PM, Mark Pryor wrote:
>> --- On Wed, 11/10/10, jayeola at gmail.com<jayeola at gmail.com>  wrote:
>>> From: jayeola at gmail.com<jayeola at gmail.com>
>>> Subject: Re: [CentOS-virt] KVM: where are the directions?
>>> To: "Discussion about the virtualization on CentOS"<centos-virt at centos.org>
>>> Date: Wednesday, November 10, 2010, 7:15 PM
>>> rpm -ql kvm
>>> rpm -qa | grep kvm
>> to continue this:
>> ------------- verify an amd64 install of kvm --------------
>> $ rpm -qa | grep kvm
>> etherboot-zroms-kvm-5.4.4-13.el5.centos
>> kvm-83-164.el5_5.21
>> kmod-kvm-83-164.el5_5.21
>> $ sudo lsmod | grep kvm
>> kvm_amd                69416  0
>> kvm                   226336  2 ksm,kvm_amd
>> yum install bridge-utils tunctl
>> ------------- snip ---------
>> kvm is basically qemu.
>> The kvm launcher is (by default) not in your path:
>> /usr/libexec/qemu-kvm
>> request help on qemu-kvm and you will see almost the same thing which is in qemu.
>> Trying to learn kvm via libvirt is over-kill - stick with the commandline.

You'll never need to run it from the command line, use the available
management tools (libvirt+virsh from the command line,
libvirt+virt-manager from X11), it makes your life much much easier.
I've been running qemu-kvm from the command line for several years,
and while it's fine to know how the system works, then you definitely
don't want to manage your enterprise virtual machines that way. For
example, if you start qemu-kvm twice in parallel, with the same HDD
image, you'll damage or destroy your HDD image. Libvirt takes care of
such banalities and many others.

> Fedora 13 Live CD:
> qemu-kvm -cdrom ./Fedora-13-i686-Live-XFCE.iso  -boot d -m 384 -net
> nic,model=rtl8139  -localtime -usb
> Froze up at "automatic boot in 10 seconds". This is probably because my
> CentOS 5.5 is 32 bit and I am running a really old version of qemu-kvm.

No, you're not running an old version of qemu-kvm in CentOS. Like most
other packages, Red Hat has selected an (old and stable) version as
the baseline version and then backported bugfixes and new features
from newer versions of the package, to fulfill the needs of their
enterprise customers. kvm-83 in CentOS is NOT equal to upstream
kvm-83. That said, as you've probably already read in the docs, KVM is
a "technology preview" in RHEL 5.x...6.0 will be the first version
with official/stable KVM support by Red Hat.

Best regards