On Thu, May 13, 2010 at 12:02 PM, Mike Snitzer <snitzer@redhat.com> wrote: > On Thu, May 13 2010 at 11:52am -0400, > Richard Shaw <hobbes1069@gmail.com> wrote: > >> There does not seem to be much information available on the status of >> LVM snapshot merging available. I looked at the patches available from >> the original author and both my kernel and LVM versions are newer than >> what he provides patches for. > > I'm not sure where you're looking for status but both the upstream > linux-2.6 and LVM2 sources are quite public. I only did google searching so I didn't get to the source level... > The snapshot-merge target support was included in Linux v2.6.33. > The corresponding LVM2 support was fully baked with v2.02.62, there were > also 2 fixes in v2.02.64. That explains it for me. I'm running Fedora 12 so my current kernel/lvm versions are 2.6.32 and 2.02.53 respectively. It looks like Fedora 13 will have the required versions, but I actually would like the merge option in order to upgrade to F13 beta with the ability to roll back. >> In lieu of the feature being available, does anyone know if it would >> be possible to use rsync to effectivly merge a snapshot volume with >> its origin volume? >> >> If so, my plan was to try an extensive upgrade of my system on the >> snapshot volume. If all goes well, I would then rsync the snapshot >> back to the origin, update my fstab, and remove the snapshot. If it >> does not go well, that's the easy part, just drop the snapshot and go >> back to the origin. > > I'm not going to comment on using rsync as a poor-man's rollback > mechanism. The snapshot-merge support is widely available so I think > it'd be great if you gave it a try. > > So rsync aside, the problem with your proposed approach is two-fold: > 1) having your package manager install into the snapshot LV. > 2) getting your system to boot off the snapshot LV. > > These aren't insurmountable problems but they would need to be overcome > and things _could_ get dicey. > > Generally the process is inverted: you make the changes to the system > (after having created a snapshot). If you don't like the changes you > use 'lvconvert --merge ...' to merge the snapshot back to origin on the > next reboot (reboot needed for the root LV). This gives you instant > rollback. Thanks for the info! I may get brave and try to install the F13 kernel and lvm2 package and see if I can get away with it. I will have to update udev as well, right? Thanks, Richard _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
