Feature changed by: Thorsten Kukuk (kukuk) Feature #318392, revision 6 Title: Install into btrfs subvolume Requested by: Thorsten Kukuk (kukuk) Partner organization: openSUSE.org Description: If you do a rollback of SLE12 the very first time, the original root volume is no longer reacheable and will never be automatically removed, means we have a disk space leak here. The reason is, that the original installation is not a subvolume/snapshot and thus will not show up in /.snapshots. If we install on btrfs, and snapshots/rollback is enabled, we should instead install into a subvolume /.snapshots/1/snapshot and make that the new root. + If btrfs is the root filesystem and "Enable snapshots" is selected in + the proposal, we should do the following: + * Inclulde snapper in inst-sys (import when needed, remove after it is + used) + * right after libstorage has created the root filesystem: + * snapper must be called to create the config + * snapper has to create a first read-write snapshot + * snapper has to set that snapshot as new default root subvolume + * The subvolumes have to be created in the initial root filesystem, + else we cannot delete the initial snapshot later. See bnc#910602, + comment 8. + * The subvolumes have to be mounted in the first read-write snapshot + * YaST has to install into this first read-write snapshot (/. + snapshots/1/snapshot), not into "/" Business case (Partner benefit): openSUSE.org: Fix a very huge disk space leak problem. Discussion: #1: Thorsten Kukuk (kukuk) (2015-01-23 14:58:31) Arvin, I think you can describe better, how the initial instannation into a subvolume has to look like, that we see it later in /.snapshots/ ? #2: Arvin Schnell (aschnell) (2015-01-26 18:13:31) (reply to #1) I would implement this as follows: Required steps during installation: * right after libstorage has created the root filesystem, snapper must be called to create the config, a first read-write snapshot and set the default subvolume * the root filesystem must be mounted to use the new default subvolume * snapper must not be called again later by YaST Problems: * libstorage does not know whether snapshots/rollback are enabled, new API required * snapper does not have the required command, needs implementation * snapper does not work with a chrooted target, needs implementation * snapper is needed in the instsys (not even all requirements are there) The problems make it difficult to do a proof-of-concept test. Further question: * Should there only be the option "rollback on / off?" or should it also be possible to configure snapper without rollbacks (that is installing into subvolume)? * There is no easy way for the user to enable rollbacks later on. Is that OK? #3: Lukas Ocilka (locilka) (2015-01-27 11:00:14) (reply to #2) To solve the "not in inst-sys" problem vs RAM used by inst-sys, I suggest using `extend` to import snapper and libs into the inst-sys ONLY when btrfs (and snapshots + rollback) are requested and remove it after it's used. We do the very same while checking for user/root password. -- openSUSE Feature: https://features.opensuse.org/318392