Synchronization and Backup on Mac OS X

Note that not all the methods listed here fully support backup of Resource Forks.

Apple .Mac Backup

Using the Backup tool that is obtained as part of the Apple .Mac product is possilbly the most simple method of backing up a personal Apple machine. It can be used to backup important files to optical media, local hard disks or network locations. Network locations can include DICE network filesystems or Apple iDisk remote storage.

-- CarwynEdwards - 27 Sep 2005

Super Duper

I've been very happy with SuperDuper! for my main disk backups. Of course, its an effort to keep up an effective procedure - but here's what I do (after I got scared by a disk crash).

-- PaulAnderson - 4 Feb 2009

Rsync

Mac OS X comes with the rsync command line file copy tool. For information on using the standard command line rsync to backup files see CommonRsyncBackup.

Prior to Mac OS X 10.4 (Tiger) the default installation of rsync does not support Resource Forks or HFS+ extended filesystem attributes. While the vast majority (if not all) user data will be maintained using rsync without Resource forks some things can not be preserved when not using a tool that supports them.

To ensure copying of Resource Forks and HFS+ extended filesystem attributes you need to do two things:

1. Use the -E command line parameter when using rsync on Mac OS X 10.4.
2. Use a destination filesystem that also supports Resource Forks and HFS+ filesystem extended attributes.

Obviously the best way to make sure you are copying the elements you want to preserve is to test the backup copy. Be very careful when doing this making sure you have a good known copy in at least one safe location.

One of the tools often suggested to simplyfy use of rsync on Mac OS X is RsyncX. This is a GUI for generating rsync scripts. Be warned development of this tool seems to have ceased and the download links have been removed. Because of this I would recommend avoiding this tool.

A command line tool that may be worth looking at to simplyfy using rsync is rsyncbackup. This is a perl script that allows a more abstract configuration of sets of files to backup. The documentation for this tool again mentions RsyncX, this part should be ignored as rsync in Mac OS X 10.4 supports Resource Forks natively.

-- CarwynEdwards - 27 Sep 2005

Unison File Synchronizer

Unison, courtesy of Benjamin Pierce is a file-synchronization tool for Unix and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other.

I have Unison installed using FinkCommander - as a by-product this also gives you an installation of ocaml. Unison is an "unstable" packackage installed from source, so to install it you first need to install Apples's XCode and X11 SDK (from the Tiger installation disks) to provide the compilers, headers etc neded to build the application. Then in Fink Commander Preferences select "Use unstable packages" (Fink tab). From the menus run Source>SelfUpdate then Source>UpdateAll. Finally, select the unison package then install from source (click the .h icon).

To use unison to synchronise your mac with your DICE files, run unison from the command-line in an X terminal window using the staff.ssh.inf.ed.ac.uk server. The DICE unison installation may not be the latest, so use 'unison-[version]' to run a matching version on the Mac. (eg I currently use unison-2.10.2)

-- MichaelFourman - 17 Sep 2005

Retrospect Backup Service

TODO: Toby - can you write something about this?