On Mon, Feb 17, 2020 at 10:03:27 +0100, Marc Roos wrote: > Hi Peter, > > Should I assume that the virsh domfsfreeze, does not require the > qemu-agent service in the guest?
No. That's the official way how to drive the "guest-fsfreeze-freeze" agent command via libvirt, thus you must have the guest agent the same way as you used it before. Using qemu-agent-command is a backdoor for testing arbitrary commands and thus you can break things. You are on your own if stuff breaks using that approach. > PS. I couldn't find the result. Afaik it looks like it is returning the > amount of frozen/thawed filesystem's qemu.git/gqa/qapi-schema.json says: ## # @guest-fsfreeze-freeze: # # Sync and freeze all freezable, local guest filesystems. If this # command succeeded, you may call @guest-fsfreeze-thaw later to # unfreeze. # # Note: On Windows, the command is implemented with the help of a # Volume Shadow-copy Service DLL helper. The frozen state is limited # for up to 10 seconds by VSS. # # Returns: Number of file systems currently frozen. On error, all filesystems # will be thawed. If no filesystems are frozen as a result of this call, # then @guest-fsfreeze-status will remain "thawed" and calling # @guest-fsfreeze-thaw is not necessary. # # Since: 0.15.0 You might also want to have a look at 'guest-fsfreeze-freeze-list'. > > -----Original Message----- > Cc: libvirt-users > Subject: Re: guest-fsfreeze-freeze freezes all mounted block devices > > On Fri, Feb 14, 2020 at 22:14:55 +0100, Marc Roos wrote: > > > > I wondered if anyone here can confirm that > > > > virsh qemu-agent-command domain '{"execute":"guest-fsfreeze-freeze"}' > > Note that libvirt implements this directly via 'virsh domfsfreeze'. This > is the corresponding man page entry: > > domfsfreeze domain [[--mountpoint] mountpoint...] > Freeze mounted filesystems within a running domain to prepare for > consistent snapshots. > > The --mountpoint option takes a parameter mountpoint, which is a > mount point path of the filesystem to be frozen. > This option can occur multiple times. If this is not specified, > every mounted filesystem is frozen. > > > > Freezes all mounted block devices filesystems. So if I use 4 block > > devices they are all frozen for snapshotting. Or just the root fs? As a side note. For snapshotting via virsh snapshot-create use the --quiesce option which does what you want or the virsh command with arguments if you don't want to freeze everything. > > Since you are using agent passthrough where libvirt doesn't do any > interpretation of what happens please refer to the appropriate QEMU > agent documentation for the semantics of the command you've used. > > >