We had to change the default options for qcow2 to cache=off to avoid data corruption on host crashes. After this change, there have been reports that installations took 2 hours which previously had taken 15 minutes. Upstream qemu has performance fixes that should help here. They need to be backported to RHEL.
Posted the backports on virtualist.
Hi Kevin, Could you please provide us with a scratch build which we could test and compare against the current implementation? Thanks, Lawrence
Hi Lawrence, I have just created https://brewweb.devel.redhat.com/taskinfo?taskID=1948061. I'm doing this for the first time, so while I hope this is what you need, I'm not 100% sure about it. If it isn't quite right just let me know and I'll make another attempt at it.
Created attachment 396927 [details] windowr2 iometer result.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2010-0271.html