RFC: Btrfs snapshots feature for F13

[David Zeuthen]

(I'm not subscribed to fedora-devel-list so if you expect an answer
please Cc me)

On Tue, 2009-11-17 at 09:52 -0500, Chris Ball wrote:
> * Ray says not to invent a new system-config-blah, and instead to talk
>   with davidz about Palimpsest.  David, what do you think?

Yep, we're planning to add support to DeviceKit-disks for exposing the
(privileged) operations that btrfs may expose (locked down by polkit,
etc etc). There are also plans to expose these operations in the UI in
Palimpsest and/or Nautilus. I don't think snapshots is going to have any
Palimpsest UI (it belongs in Nautilus I think) but the multi-disk stuff
definitely will.

As always, DKD and Palimpsest is supposed to be complementary to the
command-line tools. So all this is only relevant for creating nice UIs
for managing btrfs.

(Btw there's still some work needed in udev/blkid (but hopefully not in
the btrfs on-disk format) to properly export everything we need - e.g.
things like number of block devices in the multi-disk filesystem, maybe
the "raid" level and so on. I haven't gotten around to looking at this
in detail yet. It's on my TODO list though.)

> * Several people think that the ZFS Time Slider patches to nautilus¹
>   look good, and want that for btrfs.  Sounds plausible², 

People hacking on Nautilus will have to look into this with both ZFS,
btrfs and possibly other filesystems in mind. I haven't seen anyone do
work like this and it's not trivial.

(Oh, and if it turns out that creating/destroying btrfs snaphots isn't a
privileged operation (I can't remember at this point) it would probably
make sense for Nautilus to just use the btrfs tools directly instead of
going through a system daemon. There's just no need to overcomplicate
things.)

     David