Backups in Astrophysics: A History

In the Beginning

Astro first started using Macs in the era of Mac OS X 10.4. It was specifically requested by Astrophysics that all data should be stored locally on desktop machines. In order to back up home folders, the built-in OS feature “HomeSync” was used to synchronise usersʼ home folders with a network fileserver. “Data” partitions were initially not backed up at all, except by users who backed them up manually.

Leopard

Mac OS X 10.5 “Leopard” introduced Time Machine, and a second request came from Astrophysics that this be used to back up Data partitions. This was set to back up to a new network fileserver, offsite at the Begbroke datacentre.

Problems

HomeSync and Time Machine, despite the best efforts of IT, never worked completely reliably. It was fine for some users, but frequently problematic for others, caused by large numbers of files on a disk, large data sets that changed frequently, files with names in unusual character sets, and a variety of other causes.

Whatever the causes, it was clear that the two tools were not reliable, and plans were made to replace them.

Solutions

The 2011 image for Astrophysics replaces both HomeSync and Time Machine with homegrown solutions developed within IT, based on proven and reliable open source tools. Home folders are now stored directly on the file server thus eliminating the need to synchronise them at all. This fileserver is backed up in two separate ways, a daily backup which keeps several weeks of history, and a “hot spare” clone that can be put into service in the event of hardware failure.

Data partition backups are now performed by the server regularly contacting the Macs and pulling a backup directly, meaning no special software needs to be configured. At the moment, backups can only be restored by IT personnel, but in the near future users will be able to restore their own backups, and also check on the status of what backups are available.

Categories: Apple | Astrophysics | Mac | OS X | Services