[sheepdog-users] Problem with snapshots made with qemu-img

[Liu Yuan]

On Fri, Jun 28, 2013 at 10:07:47AM +0200, Ing. Luca Lazzeroni - Trend Servizi Srl wrote:
> Hi,
> if I make a snapshot of a running VM using:
> 
> qemu-img snapshot -c Pippo Pluto.raw
> 
> snapshot is created on all nodes, but its tag is updated on all nodes except the one running the VM.
> On other nodes I can see, via "collie vdi list" the snapshot tag updated correctly, but on the node running the VM I see 2 VDI with the same name, different ID and empty Tag.

Seems that recent qemu-img need fixes, we didn't test snapshot with qemu-img
with our functonal tests. We should though.

> 
> If I create the snapshot via "collie vdi snapshot", everything works fine and tag is propagated to all nodes; but I don't know if creating a snapshot with collie of a running VM with writeback cache enabled is a good idea in terms of data integrity…

No problem, snapshot operation will
1 flush the cache first
2 mark the vdi as readonly

If there is, it is a bug that should be fixed.

Thanks,
Yuan