Thu, 31 May 2007

Virtualization Performance and the Very Low Bar

"I've clocked kbuild at within 25% of native."
    -- Avi Kivity on KVM 22 release.

I was surprised by this admission: I certainly hadn't been advertising (the similar) lguest numbers! But Avi probably knew that this was just the beginning (I don't have comparable kvm 26 numbers, but given the improvements in the virtbench results since then, I'd expect at least 5-10% more shaved off).

For virtualization I consider 25% slowdown to be poor, 15-25% to be reasonable, 10% to be good and 5% or less to be excellent. I'd hoped lguest would end up in "reasonable" for most tasks, and entertained fantasies that it might reach "good" without becoming a bloated mess.

But what's interesting here is how low the bar is. To pick my favourite at the moment, we're still very much in the experimental stage with efficient I/O: even for the "established" Xen doesn't have inter-guest I/O at all, and has been through several different schemes for networking. The schemes which ppc uses are both baroque and not obviously efficient either.

This, of course, makes it exciting. So jump in!

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