Backups
Philosophy
CSG's standard model for reliable data storage is straightforward:
The data on all desktop and laptop computers is considered expendable. Hence these machines should not contain the only copy of any vital data, but only transient working copies; if the machine is lost, stolen, or fails, then it should be possible for the owner to restore the data previously stored on it, or reconstruct it programmatically from some other reliable source.
- All data considered vital should be kept (or mirrored) on central CSG network filestores that are backed up.
CSG maintains regular backups of network volumes, both daily to on-line (disk-based) storage, and weekly to off-line (tape) storage.
What we do back up
The only filesystems we back up are the following:
Your network home-directory -- i.e. H:\ on CSG Windows machines, /homes/$USERNAME on CSG Linux machines.
All other network file-stores, i.e. shared volumes of the form /vol/NAME on Linux, e.g. /vol/dse, /vol/lesc and /vol/www. A few /vol areas have been designated as expendable, or have other backup arrangements (e.g. /vol/hci2 and /vol/vipdata are stored on a pair of equal sized RAID arrays, and each is backed up to spare space on the other). You can check whether we currently do backups for your favourite shared volume via the link at the bottom of this page.
Things which are not backed-up
- Laptop hard-drives.
- Desktop hard-drives, even when they're running a standard CSG installation. (This includes /data on CSG Linux machines.)
- Server hard-drives, even when they're running a standard CSG installation.
- Network file-stores which have been designated as expendable, e.g. /vol/bitbucket.
Please read the following new document to avoid losing your vital data: Guide to Ensuring your Vital Data is backed up
On-line backups
On-line backups are taken nightly to two servers, one in the Huxley Datacentre and the other in the Mechanical Engineering Datacentre. These backups are available as two read-only filesystems (/vol/recover1 and /vol/recover2), allowing you to restore from backup without needing CSG's assistance. To make life easier just use /vol/recover - we just choose one of the two at our discretion: 1 path to remember, but two copies of backup.
See also: Instructions for retrieving files from backups
Off-line backups
CSG run a weekly tape backup of all home directories and other shared network storage as agreed with their owners. If you require data to be restored from tape, please contact CSG with information on the files you would like to have restored and an approximate date you would like to recover from. CSG routinely keeps tapes for 6 months. Please also bear in mind that restoring from tape requires manual intervention, and so may take a day or so to perform.
Checking when your data was last backed up
We can now offer you the ability to see when each networked volume (home directory or shared volume) was last successfully backed up, on:
- both copies of the nightly on-line backups, /vol/recover1 and /vol/recover2.
- weekly off-line (tape) backups