Re KVM vs Xen, we are about to start swapping over the KVM where we can:
Pros:
- newer kernel (2.6.27 vs 2.6.18)
-- I already have to backport 3 fixes at home for Xen
- it has a future (see above)
- it's shiny!
- Xen still ain't mature IMO even now (e.g. when a domain refuses to
boot - though TBH I havn't had that problem for some time now)
Cons:
- no PCI passthrough with IOMMU chips (which most PCs don't have)
-- and the support hasn't finished being written yet
-- (yes I use this currently in Xen to pass ethernet cards through to
firewall VMs)
- KVM _requires_ hardware support in the CPUs
-- from personal experience you have to be _very_ careful. e.g. brand
new Intel E6000s do have it, but E7000s do not.
- it's shiny!
- KVM is still too new to be mature
Performance wise it's 50/50 - i.e. it very much depends on your
workload - and IIRC it depends on what CPU you run too. However I
suspect that KVM will get faster over time (and Xen will lose any
major advantage it might have had) and Xen will die.
We don't have a huge number of servers where we can do this, but I'll
try and remember to post when we've got some experience.
Adrian
--
Email: adrian@??? -*- GPG key available on public key servers
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