linux-aio usable?

Bernhard Schmidt
2010-03-08T01:46:54Z

Hi,

sorry for this pretty generic question, I did not find any real pros and
cons on the net anywhere, but I might just have missed them.

In a pure x86_64 environment (~2.6.32 vanilla kernel, 0.12.3 qemu-kvm),
is enabling linux-aio in KVM a good idea? What are the
advantages/disadvantages? Are there any potential pitfalls?

The reason I'm asking is that there has been some traffic on the list
about it, so it seems to be something people want to get working.
qemu-kvm in Ubuntu Lucid is currently not compiled with that option.
I've made a local version with aio and it seems to work fine (and
performs a bit better at first glance).

Is there any reason one should not compile that feature by default?
Does it do anything if not explicitly run with aio=native?

Best Regards,
Bernhard