Am 13.03.2018 um 13:12 hat Jeff Cody geschrieben: > From: Liang Li <liliang.opensou...@gmail.com> > > When doing drive mirror to a low speed shared storage, if there was heavy > BLK IO write workload in VM after the 'ready' event, drive mirror block job > can't be canceled immediately, it would keep running until the heavy BLK IO > workload stopped in the VM. > > Libvirt depends on the current block-job-cancel semantics, which is that > when used without a flag after the 'ready' event, the command blocks > until data is in sync. However, these semantics are awkward in other > situations, for example, people may use drive mirror for realtime > backups while still wanting to use block live migration. Libvirt cannot > start a block live migration while another drive mirror is in progress, > but the user would rather abandon the backup attempt as broken and > proceed with the live migration than be stuck waiting for the current > drive mirror backup to finish. > > The drive-mirror command already includes a 'force' flag, which libvirt > does not use, although it documented the flag as only being useful to > quit a job which is paused. However, since quitting a paused job has > the same effect as abandoning a backup in a non-paused job (namely, the > destination file is not in sync, and the command completes immediately), > we can just improve the documentation to make the force flag obviously > useful. > > Cc: Paolo Bonzini <pbonz...@redhat.com> > Cc: Jeff Cody <jc...@redhat.com> > Cc: Kevin Wolf <kw...@redhat.com> > Cc: Max Reitz <mre...@redhat.com> > Cc: Eric Blake <ebl...@redhat.com> > Cc: John Snow <js...@redhat.com> > Reported-by: Huaitong Han <huanhuait...@didichuxing.com> > Signed-off-by: Huaitong Han <huanhuait...@didichuxing.com> > Signed-off-by: Liang Li <liliang...@didichuxing.com> > Signed-off-by: Jeff Cody <jc...@redhat.com> > --- > > N.B.: This was rebased on top of Kevin's block branch, > and the 'force' flag added to block_job_user_cancel
Thanks, applied to the block branch. Kevin
