Hi list, I just had a try at converting my old TW installation on the laptop (installed 2016.08) to the new one-var-only subvolume scheme. (I have deleted all snapshots except the currently used one before starting, maybe daring, but I didn't want that to interfere. In hindsight leaving one around should be the safer option? But you cannot roll back to those anyhow after the subvolumes are deleted...) /var is in use permanently, so I decided to do this offline, booting from another system (install system / USB should be fine) I used the test install I did yesterday, on external USB disk /dev/sdb. My old, main system (i.e., the btrfs root) is on disk /dev/sda4 Here's what I did: # mount top level mount -o subvol=/ /dev/sda4 /mnt # /var exists, so new name btrfs subvolume create /mnt/@/newvar # Now fill the new /var with old content from snapshot and var subvolumes. # I'm still on the original snapshot, never did a rollback. So: rsync -avr /mnt/@/.snapshots/1/snapshot/var/ /mnt/@/newvar/ rsync -avr /mnt/@/var/ /mnt/@/newvar/ # Set the no-copy-on-write flag chattr -fR +C /mnt/@/newvar # adapt fstab to the new layout vi /mnt/@/.snapshots/1/snapshot/etc/fstab # comment out all the old /var/* subvolume mounts, and add UUID=<your-uuid-same-as-others> /var btrfs subvol=@/newvar 0 0 At this stage I rebooted back to the old system, which is where I'm typing now I got a complaint that /var was not empty when @/newvar was mounted over, but that is harmless (and expected). So far I have no issues at all, and I will now continue to remove the old subvolume and double data. This can in principle be done from the running system, but I also want to change the name of newvar to var, after all subvolumes are deleted. So I'll boot the other system once more and mount -o subvol=/ /dev/sda4 /mnt btrfs subvolume list / | grep /var/ | cut -d@ -f2 | \ while read v; do brtfs subvolume delete /mnt/@${v} ; done btrfs subvolume sync /mnt rm -rf /mnt/@/var mv /mnt/@/newvar /mnt/@/var # official(?) way to rename subvolumes # the snapshot still has some data in /var. Delete it rm -rf /mnt/@/.snapshots/1/snapshot/var/* # Dont forget to change mount entry sed -i -e 's/newvar/var/' /mnt/@/.snapshots/1/snapshot/etc/fstab # newvar->var umount /mnt reboot curageous people might do this already in the first part - I wanted the old stuff to be around in case I mess up.... Don't follow this blindly, but maybe some find it usefull to convert their own system without re-installing from scratch... Cheers, Pit -- Dr. Peter "Pit" Suetterlin http://www.astro.su.se/~pit Institute for Solar Physics Tel.: +34 922 405 590 (Spain) P.Suetterlin@royac.iac.es +46 8 5537 8558 (Sweden) Peter.Suetterlin@astro.su.se -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org