| Carl Friedrich Gauß Faculty | Department of Computer Science

Disk Backups

AuthorFrank Steinberg
KeywordsBackup Datensicherung

Almost all essential data is stored on a ZFS server, which is accessed by NFS and SMB. ZFS allows to synchronize dataset changes to remote systems which hold mirrors of the primary datasets. We us this technique to implement backups to two backup systems, one located in the local network running multiple backups per day, and one located at GITZ running one backup each night.

Users do not have to care about these backups, in general. What could be of interest, is the ZFS snapshot capability: At each root directory of a ZFS filesystem, there is a "hidden" directory .zfs (you cannot see it in a directory listing, but you can access and "cd" into it). Within that directory you will find regular snapshots, which represent former read-only copies of the filesystem. You can use these snapshots to restore accidentally removed or modified filesystem content.

Apple TimeMachine

MacOS users can use a special Samba server for TimeMachine backups. If you want to use this service, then please

  • login to a Linux server, e.g. linux.ibr.cs.tu-bs.de, and create the target directory by mkdir $HOME/.timemachine,
  • limit the maximum backup storage size by sudo defaults write /Library/Preferences/com.apple.TimeMachine MaxSize 409600 (GB * 1024, e.g. 400GB: 400 * 1024 = 409600).
  • let Frank Steinberg know, if your quota limit is not sufficient,
  • configure your TimeMachine client to use the TimeMachine volume on zfs1.local and activate it. You may also configure the target from the command line explicitly to avoid the need for being attached to the IBR LAN directly (e.g. when connected via OpenVPN):
    sudo tmutil setdestination -a -p smb://username@zfs1.ibr.cs.tu-bs.de:4445/TimeMachine

last changed 2020-03-24, 11:01 by Frank Steinberg