On Fri, Jan 16, 2015 at 12:47 AM, aurfalien <aurfalien@xxxxxxxxx> wrote: > Hi all, > > I thought I’d post this in case any one has issues similar to mine. > > First, my initial email to the list which I didn’t send; > > I’m trying to run a KVM based guest OS off of a mirrored ZFS dataset. > > It won’t run with errors "invalid argument..", but will run when on the root > volume, or when that ZFS dataset has been removed in favor of an EXT4 > volumes. > > Thanks in advance, > > PS I do see this thread which is not promising; > > http://www.redhat.com/archives/redhat-list/2014-July/msg00017.html > > Lastly, the solution; > > Set your cache policy on the KVM guest as write back. > > This allows it to run on a ZFS volume. > > My apology if this has been covered. I did spend some time on this so > hopefully you can save time by setting the cache policy. The virt-manager / KVM angle is covered here: https://github.com/zfsonlinux/zfs/issues/224 It looks like virt-manager asks for "cached=none" by default, which causes qemu to pass the "O_DIRECT" flag when opening the file, which ZFS doesn't support. Be advised that if you use your work-around, you may be risking problems with disk corruption unless your OS understands how to use flush commands; see cached=writeback here: https://www.suse.com/documentation/sles11/book_kvm/data/sect1_1_chapter_book_kvm.html -George _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos-virt
