On 08/24/2010 03:35 PM, Kevin Wolf wrote:
I don't know how bad the performance regression is, and how large the
integrity risk is. I'd default towards preserving integrity, but maybe
this situation is different.
I have reports of installations taking like 50 min instead of 14 min. My
own qemu-io based test goes up from 1 s to 23 s. And I think the winner
is Michael's image conversion which went up from 30 s to 49 min.
So it's not like we're talking about just some 10 or 20 percent.
Image conversion should be done with cache=unsafe (with an fsync at the
end to make sure a guest isn't launched with volatile data in the
cache[1]). The io test isn't a user workload.
The 14 min -> 50 min regression is pretty bad, but I'm not sure it's bad
enough to merit risking user data.
[1] or better, when launching a guest with cache!=unsafe start with an
fsync to make sure it's on disk.
--
error compiling committee.c: too many arguments to function
