Backups of all main servers and services are maintained by the admin. They are based on ZFS send&recv, which is very efficient. This allows us to run all backups twice per day.
Since backups are based on ZFS snapshots, users may easily restore files by themselves as long as their snapshots are kept. Snapshots can be found in the hidden(!) directory ./.zfs/snapshot/ starting from the mountpoint of the affected filesystem.
Backups of users' personal devices are the user's own responsibilty. A simple approach is to backup data into the user's $HOME directory on the IBR servers, e.g. via borg or rsync. If $HOME quota limits are not sufficient, please talk to the admins.
MacOS users may use TimeMachine while connected to the IBR LAN. A TimeMachine service located on ZFS1 should be found and can be used. Each user may occupy up to 2 TB this way, but you are solicted to set your own reasonable limit. You may use sudo tmutil destinationinfo and sudo tmutil setquota <ID> <GB> to see and adjust your limit.