[pve-devel] Snapshot questions
philipp.marek at linbit.com
Fri Sep 4 08:43:25 CEST 2015
I'm currently implementing the snapshot functions for the DRBD backend; but
a few questions have popped up, so I'm asking them here.
*) The first question is - how would these get called? "pvesm" shows no
matching arguments, and the GUI has no "snapshot" buttons either.
Does that hide behind backup functionality or something like that?
*) The second question is - recently the "filesystem_path" function got a new
die "drbd snapshot is not implemented\n" if defined($snapname);
In what circumstances would that function get called? While the Thin LVM
snapshots that DRBDmanage uses might be addressable locally, accessing
them is not recommended. Is that just for information purposes in the GUI?
*) Thirdly, about restoring snapshots...
There's the volume_snapshot_rollback() function that will destroy the
volume's data and replace it with the data in the snapshot - but using
a snapshot for a new ("clean") VM isn't being done, right?
During volume_snapshot_rollback() there will no one be accessing the
original volume, and after rollback it can have a new filesystem_path(),
Thanks for any information!
Ad 1: Or might not, if the given machine doesn't have _that_ snapshot (eg.
because it was turned off at that time).
More information about the pve-devel