Re: [libvirt] CPU compare and baseline
Ok, I didn't understand how to use "cpu-baseline",
it's not clear in
the help command.
So "cpu-baseline" give me the CPU XML file I need to use to be able to
migrate between two hosts but how I use this XML file ?
You can just stick the output of cpu-baseline to guest's XML file, so you
could have something like the following:
<domain type='kvm'>
<name>domain-name</name>
<memory>262144</memory>
<currentMemory>262144</currentMemory>
<vcpu>2</vcpu>
<os>
<type arch='x86_64' machine='pc-0.12'>hvm</type>
<boot dev='cdrom'/>
</os>
<cpu match='exact'>
<model>Opteron_G2</model>
<feature policy='require' name='ht'/>
<feature policy='require' name='vme'/>
<feature policy='disable' name='svm'/>
<feature policy='disable' name='rdtscp'/>
</cpu>
...
</domain>
Another question, why Libvirt consider CPUs with non-matching
vendors
cannot be compatible ?
That's because CPUs made by different vendors are not generally compatible.
Migration between them may work but it's not guaranteed. Libvirt allows you to
choose whether you want to stick with a single CPU vendor or not. If you put
<vendor> tag into the <cpu> element above, libvirt will forbid migration to a
CPU made by a different vendor. If no <vendor> tag is present, CPU vendor is
not checked during migration.
Jirka