[lxc-devel] [PATCH] [RFC] snapshots: move snapshot directory (v3)

[Serge Hallyn]

Quoting S.Çağlar Onur (caglar at 10ur.org):
> Hey Serge,
> 
> On Sat, May 24, 2014 at 8:15 PM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> > Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
> >> Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
> >> > Originally we kept snapshots under /var/lib/lxcsnaps.  If a
> >> > separate btrfs is mounted at /var/lib/lxc, then we can't
> >> > make btrfs snapshots under /var/lib/lxcsnaps.
> >> >
> >> > This patch moves the default directory to /var/lib/lxc/c/snaps.
> >> > If /var/lib/lxcsnaps already exists, then use that.
> >> >
> >> > If we are deleting a container which has snapshots, we currently
> >> > will delete the container itself and its rootfs, but not its
> >> > snapshots.  This could be confusing for the user, and there is
> >> > no option to c->destroy() to ask for different behavior.  So
> >> > currently a user would have to delete all snapshots first, then
> >> > delete the container.  Ideas for better handling this would be
> >> > welcome, but we don't want to change the current api, so while
> >> > adding a new c->destroy_full() would be ok, adding a flags
> >> > argument to c->destroy(c, flags) is not.
> >>
> >> I'm thinking that
> >>
> >>       c->snapshot_destroy(c, NULL);
> >>
> >> should tell lxc to remove all snapshots.  So then at least we can
> >>
> >>       c->snapshot_destroy(c, NULL);
> >>       c->destroy(c);
> >>       lxc_container_put(c);
> >>
> >> as a way of making sure we delete the whole thing.
> >
> > I'm working on a full patch to go about it this way.
> 
> Sorry for being late in the game but I'm wondering would be make more
> sense to introduce a new method called lxcapi_snapshot_destroy_all to
> do lxcapi_snapshot_list followed by a loop to call
> lxcapi_snapshot_destroy instead of overloading the snapname parameter?

Hm, we could do that.  Note that since snapshots are always called
snap%d, 'ALL' can't realistically be in use unless the user has
manually created a container into the snapshot path.

I don't have strong feelings either way.