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Backups

A feature of AFS is that the system makes backup images of all volumes every night. This image is available to you, online, in your backup volume for 24 hours after the image was made. After 24 hours, a new image is taken and the new image replaces the older one.

Your backup volume is mounted in your home directory under the directory ~/.backup. Although it contains a copy of everything in your account from the day before, it does not consume any of your quota.

Determining when your backup image was last taken

To find out when your home directory's backup image was last taken, type this command at the system prompt:

vos examine user.<username>.backup

Where <username> is your primary (cluster login) SUNetID.

About five lines down there will be a line which begins with the word "Creation" followed by a date and time. That is the date and time when your backup image was made; the time is represented in terms of a 24 hour clock and should always be some time in the very early morning.

Finding the backup volumes for class or group directories

Backup images are also made for most other volumes, although they aren't mounted automatically. If you want to check the backup image for your class or group directory, replace "user.<username>" with the name of your volume in the vos examine statement above (don't forget to append the ".backup" part!). If you have administrative access to this group or class volume, you can mount it by going to the mountpoint directory (/afs/ir/group/<groupname>), and if there isn't already a directory called ".backup", mount it with:

fs mkmount -dir .backup -vol <volume name>.backup

If you don't know the volume name for your class or group volume, the easiest way to find it is:

fs listquota <path to group or dept volume>

The Volume Name for that directory will be listed along the lefthand side of the output.

Restoring files from your backup image

If you deleted a file before the time that your backup image was made, your file will NOT be available in your .backup directory.

If you created a file AND deleted it between the time one backup image was taken and the next time a backup image was taken, it will NOT appear on backup tapes anywhere: you will have to recreate it because no one can recover it for you.

If the file had existed for at least 24 hours, a version of it should be on backup tapes somewhere. If you really need the file back, submit a HelpSU request detailing the full path and name of the file and the last time you are absolutely certain that you had the file. Be aware that file restores are done on an as-possible basis, and you may have to wait some time for your file to be restored.

If you deleted a file after the time that your backup image was made, whatever version of the file that existed the previous day will be in your .backup directory. You need to hurry and retrieve it before the next backup image is taken.

If you need help finding things in your backup volume, or mounting your backup volume, submit a HelpSU request.

Last modified January 22, 2010