snapsh

Btrfs snapshot managing bash script

Requirements:

• bash
• GNU setopt - part of GNU coreutils
• btrfs-progs- Userspace programs for btrfs

Instructions:

• Script needs the toplevel subvolume (id=5) mounted somewhere. Default location is /root/btrfs-toplevel, but you can mount it anywhere you like and define it with TOPLEVEL variable. (A separate config file will be implemented later).
• Will create a subvolume named snapshots by default to the toplevel. This can also be changed with SNAPSHOTS_LOCATION.
• Display usage instructions with snapsh -h or snapsh --help
• Taking snapshots requires root priviledges. Take a snapshot with snapsh -s SUBVOLUME or snapsh --snapshot SUBVOLUME, where SUBVOLUME is the name of the source subvolume. You can add a description for the snapshot with the -d | --description option
  
  Example with Fedora default btrfs layout with root and home subvolumes:
  snapsh -s root -d "This is a snapshot"
  This will create a snapshot called root_snapshot_YYYY.MM.DD-hh:mm:ss to the snapshots subvolume (or the one you defined with SNAPSHOTS_LOCATION), with a description "This is a snapshot"
• Snapshots can be listed with snapsh -l or snapsh --list
• Delete snapshots with the -r or --remove option. List snapshots first with snapsh -l, then delete snapshot with e.g. snapsh -r 2, where 2 is the number of the deletable snapshot in the -l listing. The list numbers always start from 1 and increment from there, so always check the number before deletion. Batch deletion might be implemented later.
• Rollback to a snapshot with snapsh --rollback NUMBER, where NUMBER is the number listed in snapsh -l. The subvolume will be detected from the snapshot. E.g. snapsh --rollback 14. Script will ask to reboot system once done.
  • Rollback renames your currently active subvolume to SUBVOLUME.backup, if you want these backups to be deleted automatically, copy the included snapsh-post-rollback.service to /etc/systemd/system and systemctl enable snapsh-post-rollback.service. It will check if *.backup subvolumes exist and delete them on every boot. This is recommended to be enabled, since rollbacks also take a "regular" readonly snapshot as SUBVOLUME_backup_YYYY.MM.DD-hh:mm:ss. The unit will be enabled automatically with the --install option which will be done later.
• Snapshot type displayed in listing can be set with the -t, --type option. When used in conjunction with -l | --list, it will filter the results based on the type. E.g. snapsh -l -t manual will list all the snapshots with the type manual. Type can be one of manual, auto, boot or backup. Note that only manual and backup are implemented properly at this stage, but you can still use the other types as well.

Planned features:

• separate config file
• --install option to integrate script into system
• Batch deletion of snapshots
• systemd timer for automating snapshots
• --auto option (quiet) for automated snapshots
• Option to snapshot multiple/all subvolumes

Root access is required for btrfs-progs.

License:

GPL v3.0