Backups and Snapshots¶
Tape backups of the data storage are performed for the purposes of disaster recovery and do not provide the ability to recover old or lost files. However, we utilise GPFS snapshots, and if the file exists on an overnight snapshot, you can recover them as shown in the snapshots section
What is backed up:
- User home directories
- Shared project storage
What is NOT backed up
- Scratch Space
- auto deleting scratch space
The backup schedule consists of daily incremental backups which are retained for a month. This is currently handled by Spectrum Protect (previously TSM) to build a full backup. The tapes are kept geographically separate to our cluster.
Snapshots are taken daily and are kept for a couple of days, they hold a copy of the entire storage at the point they were taken. All files exist in the snapshots with exactly the same permissions as they did in the original, which means you can recover files from snapshots yourself.
Snapshots can be found under
/data/.snapshots which contains one directory
for each available snapshots.
These directories are named by date (any additional ones are there for
administration purposes, such as taking tape backups). Below these directories
is the same directory structure as the rest of the GPFS file store. Hence home
directories are under
These directories are read-only; they can not be changed.
A full list of available snapshots can be gathered with
this will tell you exactly when the snapshot was taken:
$ mmlssnapshot gpfsWork Snapshots in file system gpfsWork: Directory SnapId Status Created 2016-1-22 1001 Valid Fri Jan 22 23:00:20 2016 2016-1-23 1002 Valid Sat Jan 23 23:00:13 2016 2016-1-24 1004 Valid Sun Jan 24 23:00:20 2016
Recovering files from snapshots¶
To recover a file from the snapshot simply copy it somewhere outside the
cp /data/.snapshots/2016-1-24/home/abc123/lost_file /data/home/abc123/recovered_data/