Hi, I''ve written up a draft of an Fedora 13 feature proposal for filesystem rollback using Btrfs snapshots that are automatically created by yum: https://fedoraproject.org/wiki/Features/SystemRollbackWithBtrfs It''d be great to get feedback on whether this is a good idea, and how the UI interaction should work. We''re also discussing it in this fedora-devel thread: http://thread.gmane.org/gmane.linux.redhat.fedora.devel/123695 Some comments I''ve got already received, from the thread: * People want the UI to allow independent active snapshots per filesystem (i.e. btrfs /home is the live filesystem, and btrfs / is an older snapshot). * Several people think that the ZFS Time Slider patches to nautilus¹ look good, and want that for btrfs. Sounds plausible, but I''m more interested in first working on ways to let developers feel comfortable upgrading to the development version of Fedora each day with the possibility of reverting. * Instead of inventing a new system-config-blah, this should probably be part of Palimpsest². * Perhaps we should encourage people using the Fedora installer with btrfs to create a rootfs separate to their /home, so that they can rollback rootfs snapshots without affecting their homedir. Thanks! - Chris. ¹: http://blogs.sun.com/erwann/entry/zfs_on_the_desktop_zfs http://blogs.sun.com/erwann/entry/time_slider_screencast http://blogs.sun.com/erwann/entry/new_time_slider_features_in ²: http://library.gnome.org/users/palimpsest/stable/intro.html.en -- Chris Ball <cjb@laptop.org> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Goffredo Baroncelli
2009-Nov-17 18:52 UTC
Re: RFC: Btrfs snapshots feature proposal for Fedora 13
On Tuesday 17 November 2009, Chris Ball wrote:> Hi, > > I''ve written up a draft of an Fedora 13 feature proposal for > filesystem rollback using Btrfs snapshots that are automatically > created by yum: > > https://fedoraproject.org/wiki/Features/SystemRollbackWithBtrfs > > It''d be great to get feedback on whether this is a good idea, and how > the UI interaction should work. We''re also discussing it in this > fedora-devel thread: > > http://thread.gmane.org/gmane.linux.redhat.fedora.devel/123695 > > Some comments I''ve got already received, from the thread: > > * People want the UI to allow independent active snapshots per > filesystem (i.e. btrfs /home is the live filesystem, and btrfs / is > an older snapshot).On the basis of some empirical tests, I discovered that in btrfs a snapshot doesn''t doens''t affect the other subvolume(s). If / (root) and /home are different subvolumes, a snapshot of the / (root) doesn''t affect the /home content, and viceversa. So if the root and the /home directory (or better the userS directories) are separate volumes, you have the required behavior.> > * Several people think that the ZFS Time Slider patches to nautilus¹ > look good, and want that for btrfs. Sounds plausible, but I''m > more interested in first working on ways to let developers feel > comfortable upgrading to the development version of Fedora each > day with the possibility of reverting. > > * Instead of inventing a new system-config-blah, this should probably > be part of Palimpsest². > > * Perhaps we should encourage people using the Fedora installer with > btrfs to create a rootfs separate to their /home, so that they can > rollback rootfs snapshots without affecting their homedir.On the basis of my tests, I think that is sufficient to create a volume for the root (''/'') and on for the /home (or a specific subvolume for every user). Then it is possible to snapshot and "time sliding" every subvolume without affecting the others. I would like to add a my comment: in btrfs I think that "snapshot" (for the btrfs snapshot) is not the best name. I think that a better term is "branch". For example the btrfs snapshot capability may be used not only for recovering from a mistake, but also may be used for maintaining different configurations...> Thanks! > > - Chris.BR G.Baroncelli> > ¹: http://blogs.sun.com/erwann/entry/zfs_on_the_desktop_zfs > http://blogs.sun.com/erwann/entry/time_slider_screencast > http://blogs.sun.com/erwann/entry/new_time_slider_features_in > > ²: http://library.gnome.org/users/palimpsest/stable/intro.html.en > -- > Chris Ball <cjb@laptop.org> > One Laptop Per Child > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >-- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) <kreijackATinwind.it> Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512