What is backed up

All local filesystems on dogma and llama are backed up. None of the filesystems on individual computational nodes are backed up. (The individual nodes are clones of llama, the head node, so there's no need to back them up separately.)

When things are backed up

A "full" backup includes all files. An "incremental" backup includes all files modified since the last full or incremental backup. A "differential incremental" backup includes all files modified since the last backup of any kind.

Each type of backup has a frequency (how often it occurs) and a retention period (how long the backup image is kept before the media is reused).

Full4 weeks6 months
Incremental1 week3 months
Diff. incremental1 day3 weeks

Backups occur based on the interval since the last backup and based on tape drive availability on our backup server. Because your cluster is not connected to our private backup network, we start your backups during off-peak hours (10 PM - 6 AM) to reduce the impact of the increased network usage.


Finally, a reminder about our backup strategy. Our primary goal when planning backup solutions is to be able to recover from disaster situations, like hardware failure, building structural failure, fire, or flood. We will always make our best effort to restore files for users that were accidentally deleted or modified. However, we ask that you be considerate of this facility and not reduce the care with which you deal with your data.