[sheepdog-users] Snashot and backup

[Valerio Pachera]

Hi all, may anybody write me same examples on how to backup a vdi disk?
I've been looking for documentation but I didn't find anything.

To backup a vdi disk:
  1) the guest that uses it has to be off
  2) the guest may be running but it's better if it's off
  3) it doesn't matter if it's running or not

Backup can be don only from a snapshot?
  True or False

Backup is never intend like a copy of a file that I can store elsewhere.
I'm used to make copies of file (.qcow / .raw) or block devices (dd of
a logival volume) to a nas.
With sheepdog a copy is still inside the cluster, there's no way to
'export' a vdi disk to an external storage.
Is that right?

I made a clone of a snapshot of the vdi named 'squeeze'.
>From vdi list I saw
---
  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
c squeeze_clone     1   10 GB  152 MB  2.6 GB 2012-12-06 14:49    d8d65     2
---

Later I 'c' has gone away.
---
  squeeze_clone     2   10 GB  0.0 MB  2.7 GB 2012-12-06 14:57    d8d66     2
---

When is the 'c' going away?