Adventurous yet Safety-Minded

[Chris Ball]

Hi,

   >> http://fedoraproject.org/wiki/Features/SystemRollbackWithBtrfs

   > That might be very useful for OLPC users, etc.

(Just to be clear, my interest in writing up this feature proposal was
unrelated to my work for OLPC; the proposal is purely aimed at Fedora,
and we don't have any plans to switch to Btrfs on OLPC.)

   > But (and I mean this with no disrespect to anyone else) I am not
   > going to want to use it seriously when it means rolling back
   > everything that changed since installing updates (sure, if the
   > update is a kernel update and you literally rebooted the second
   > the update happened, doing nothing else - but most updates don't
   > bite me until I try to use some app later).

That's fine -- don't use it.  It will offer a solution to people whose
system is hosed enough that they're willing to put up with having to
manually pick up user files that changed since the update containing
the broken packages happened, and offering a solution for that
disasterous case is better than not offering one.  It makes it so
that more people can use Rawhide than would otherwise be able to.

   > A better solution would be to be able to rollback individual files
   > or groups of files to earlier versions

Yes, a separate piece of work would involve porting the work that Sun
did adding "Time Slider" support to Nautilus over from ZFS to Btrfs.
This allows exploring snapshots using Nautilus, and easily restoring
groups of files that way:

   http://blogs.sun.com/erwann/entry/zfs_on_the_desktop_zfs

Btrfs snapshots work extremely similarly to ZFS snapshots (each
snapshot as a separate mount), so this work isn't very complicated,
and would be valuable:  someone should do it.  It's just not what
I'm interested in working on first.

- Chris.
-- 
Chris Ball   <cjb at laptop.org>
One Laptop Per Child