Hmmm, using 'virsh domfsinfo testdom' gives me a crash in win2008r2
(using software from virtio-win-0.1.171.iso)
Fault bucket , type 0
Event Name: APPCRASH
Response: Not available
Cab Id: 0
Problem signature:
P1: qemu-ga.exe
P2: 100.0.0.0
P3: 5c473543
P4: KERNELBASE.dll
P5: 6.1.7601.24545
P6: 5e0eb6bd
P7: c0000005
P8: 000000000000c4d2
P9:
P10:
Attached files:
These files may be available here:
C:\ProgramData\Microsoft\Windows\WER\ReportQueue\AppCrash_qemu-ga.exe_bd
2e6535bdb93328680e0285e89e08f2866db83_0b0deada
Analysis symbol:
Rechecking for solution: 0
Report Id: 3d82596e-517c-11ea-b213-525400e83365
Report Status: 0
-----Original Message-----
Cc: libvirt-users
Subject: Re: guest-fsfreeze-freeze freezes all mounted block devices
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.
>
>
>
