Guest post by Phoronix talks about an upcoming feature in Fedora 13 (scheduled to be released on April 2010) that provides system rollback support via the Btfs filesystem.
Phoronix talks about an upcoming feature in Fedora 13 (scheduled to be released on April 2010) that provides system rollback support via the Btfs filesystem.
http://lwn.net/SubscriberLink/362500/6cc5cd840f5e0519/ (from behind the lwn.net paywall, for my OSnews friends)
You appear to have unaccountably dropped the ‘may’ which Phoronix correctly included in their headline. Any Fedora 13 features at present are _proposed_ features, they have not gone through the review process and may not actually be implemented.
This functionality has been in OpenSolaris for quite some time now. It really rocks hard. Make a safe quick rollback in seconds. Awesome. I can really understand why Fedora wants that functionality.
Does OpenSolaris offer package management integration with ZFS so that if a update fails, you can rollback? I am aware a Debian variant of OpenSolaris does that but does OpenSolaris itself do that?
Yes it does.
Any reference to the in-depth technical details? Any docs on how it is implemented would be useful.
The OpenSolaris source code is available. I dont know if IPS package system code is available?
Anyway, this rocks. Hard. Before every install, it gets snapshot. And each snapshot are shown in GRUB. I just choose which snapshot I want to boot into.
Also, Nexenta has this. It is Ubuntu, but with OpenSolaris kernel. You have ZFS, DTrace, etc with Ubuntu userland.
There’s also experimental support in FreeBSD for the Boot Environment auto-snapshot feature for OS upgrades. Before an OS upgrade, a new BE is created, and you get a menu at boot that lets you select which BE to use. To “rollback”, just boot into the previous BE and delete the erroneous one.
It’s not part of FreeBSD yet, but the patches and docs are out there to make it work: http://anonsvn.h3q.com/projects/freebsd-patches/browser/manageBE
And if one puts /var and /usr/local onto ZFS filesystems, one can manually snapshot /var and /usr/local before installing/upgrading apps. If something goes wrong, just rollback to the previous snapshot and try again. (Technically, you’d want to put /var/db/pkg onto a separate ZFS filesystem as that is what gets updated during a port/package install, and not all of /var.) It’s not automatic, but it’s possible.
Edited 2009-11-23 21:56 UTC
Last time I checked, Btrfs did not have support for deleting snapshots or subvolumes (which are the same to Btrfs). I haven’t been following Btrfs development, so it may now be implemented. It seems like that would be required for this to be very useful…
Also, Btrfs snapshots are per subvolume. Why not have separate subvolumes for /, /boot, and each /home/some_user? This would allow system rollbacks without affecting user data, and would make it possible to allow each user to make snapshots of their own home directory.
Also, does GRUB2 support Btrfs? If it does, next time I install Ubuntu, I’m going use the idea above and maybe write some scripts to implement this with APT.
Yes, Btrfs does support that and if this proposal is accepted, Fedora contributors will patch GRUB to work seamlessly.
Do the GRUB patches exist now? Or are they waiting for the proposal to be approved? (And will they/are they for GRUB Legacy or GRUB2?)
Keep an eye on
https://fedoraproject.org/wiki/Features/SystemRollbackWithBtrfs