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Offsite Backup

Overview

The departmental backup system is designed to regularly back up data (not software and operating systems) to a disk & tape system hosted over the road in the Cambridge Systems Biology Centre. For the purposes of these pages "Backup" (as opposed to "archival") is copying data from rapid access systems onto cheaper storage in order to recover from accidents or system failures. Copies are only kept for a limited period of time.
Servers are backed up in the evening:
  1. On Tuesdays, Wednesdays and Thursdays the changes since the previous backup are saved to off site disk. This information is kept for a month, and can be retrieved within 1 working day.
  2. On the second and fourth Fridays all changes since the last full backup are saved to off site disk. This information is kept for 3 months, but will be moved onto tape if disk space becomes low. It can take a day or two to retrieve.
  3. Every three months, on the first Friday, a complete copy of the data is stored to off site tape. This information is kept for a year. The specific month varies by server in order to spread the load, see the table below. Retrieval of this data is likely to take many days.

Desktops are backed up around lunchtime:

  1. On Wednesdays, Thursdays and Fridays the changes since the previous backup are saved to off site disk. This information is kept for a month.
  2. On the second and fourth Tuesdays of a month all changes since the last full backup are saved to off site disk. This information is kept for 3 months, but will be moved onto tape if disk space becomes low.
  3. On the first Tuesday of January, April, July and October a complete copy of the data is stored to off site tape. This information is kept for a year.
If more than 100 gigabytes is to be backed up the system must be on a gigabit (1000 megabit/second) rather than a 100 megabit/second network connection, otherwise they'll block the tape system for more than 3 hours. Outside flybase and the server cabinet there are limited 1GB connections available.
I get a report on every backup that occurs and check a random file every month to ensure things are ticking over OK.

Do you need it?

  1. If you're storing data on larch then your data is already backed up except for contents of folders containing a ".nobackup" file or folder.
  2. If you are using a PC with the "DEPT" login, data in your "Documents" and "Desktop" folders is on the server "Larch" so is already backed up (See #1 above.) If you are storing elsewhere then it will not be.
  3. Some lab servers are backed up too. Ask in your group. If no one knows then you have a problem in your lab.

Compared to using a hard disk

  • Data offsite can only be written to by the backup software. If you get a virus that attempts to destroy or encrypt your data it can't directly attack backups through this system
  • If you are backing up to a USB disk or NAS viruses can quite quickly delete and overwrite things.
  • It is slower and more complicated to recover data from the backup system.
  • Doing both is not harmful
  • If you manage your own backups you need to check they are working.