Backup system

The CSL's long-term backup system currently consists of backing up data to tapes. Data is backed up to Exabyte Mammoth tapes that are stored in the Exabyte EXB-480 Tape Drive, but there are also some older backups on VXA tapes, which can be read by the drives in emperor or king. VXA tapes hold more data per tape than the Mammoths, but only one can be loaded in the drive, whereas the Mammoths are controlled by the Exabyte carousel.

Backups are run every day from emperor via cron for the various backup backends we have running.

Tape Layout
The Exabyte drive has 80 slots of normal tapes: Storage Elements 2-81. They are used as follows:
 * Elements 2-41 are used by the OpenAFS backup system. They are specified by using their barcode IDs in the barcode file for exabyte-mount.
 * Elements 42-56 are labeled for use in the AMANDA system, although AMANDA is only configured to use 10 tapes, for now. They are labeled CSL01 through CSL15 by the amlabel program. AMANDA is sure to only use tapes that are labeled correctly, but the slots to use are given to chg-zd-mtx so it can find the tapes.

All of the old "cronos" data is also believed to be backed up on a single VXA tape (or will be backed up there if it can't be found). It also may be a good idea to backup some other one-time information to VXA tapes, as to not clutter the Exabyte drives.