4
Snapshots/Rollback with
Snapper
Being able to do le system snapshots on Linux providing the ability to do rollbacks
is a feature that was often requested in the past. Snapper, in conjunction with the Btrfs
le system now lls that gap.
Btrfs, a new copy-on-write le system for Linux, supports le system snapshots (a
copy of the state of a subvolume at a certain point of time) of subvolumes (one or more
separately mountable le systems within each physical partition). Snapper lets you
manage these snapshots. Snapper comes with a command line and a YaST interface.
By default Snapper and Btrfs on openSUSE are set up to serve as an “undo tool” for
system changes made with YaST and zypper. Before and after running a YaST module
or zypper, a snapshot is created. Snapper lets you compare the two snapshots and pro-
vides means to revert the differences between the two snapshots. The tools also provide
system backups by creating hourly snapshots of the system subvolumes.
4.1 Requirements
Since Btrfs is the only lesystem on openSUSE supporting snapshots, it is required
on all partitions or subvolumes you want to “snapshot”.
4.1.1 snapshots and Disk Space
When a snapshot is created, both the snapshot and the original point to the same blocks
in the le system. So, initially a snapshot does not occupy additional disk space. If data
Snapshots/Rollback with Snapper 97
