[libvirt-users] backup KVM qcow2 over btrfs or zfs

[Francesco Morosinotto]

Hi everybody,

I'm trying to implement in the non profit organization where I work a
backup strategy for our VMs.

At the moment I weekly backup the machine (on sunday nights) by stopping
the vm, making a snapshot, exporting the xml descriptor file and syncing
these files to a remote backup server.

I would really like to make daily snapshot without shutting down the vms.
at the moment the vms qcow2 disks are stored over an ext4 partition but
I'm planning to move them over a das with a new generation filesystem.

I'm trying out zfs and btrfs looking for the best one (at the moment zfs
seems to be more stable and somehow easy, flexible, while btrfs seems to
have better performance on my linux box).

I'm choosing one of these two FS in order to use theire instant-snapshot
feature;
my project will be to  pause the vm, dump the memory and the xml
descriptor file, make a snapshot of the subvolume storing the qcow2 file
and the resuming the machine back (in I hope less than 10 seconds of
downtime).

what do you guys suggest me?

Am I going to experience bad performance having qcow2 over btrfs?
I was reading something like that but the posts were really backdated...

any hints is really appreciated

Thank you

Francesco