Comment 25 for bug 532733

Alternatively, aio=threads is your other option. Perhaps try that too?

Also, perhaps play with the cache, which can be cache=none, cache=writethrough, or cache=writeback.

(Sorry, in my last post, I wrote cache=off).

See:
 * http://manpages.ubuntu.com/manpages/lucid/en/man1/qemu.1.html