AFS gets backed up nightly, and most AFS spaces (group, dept, and user) have a hidden directory, named .backup, that provides instantaneous access to the previous night's backup.
Here's what to do if that .backup directory does not appear.
SSH into one of the timeshares (e.g., corn), cd to the root directory of the dept/group/user, and run the following command:
fs mkmount -dir .backup -vol <name-of-volume>.backup
For example, to get the name of the volume for group/foo:
corn24:/afs/ir/group/foo> fs examine . File . (2004532831.1.1) contained in volume 2004532831 Volume status for vid = 2004532831 named group.foo Current disk quota is 600000 Current blocks used are 358406 The partition has 493932281 blocks available out of 799331216
Note, the name of the volume is group.foo
(another quick way of getting the volume name is: fs lq as in listquota)
corn24:/afs/ir/group/foo> fs lq Volume Name Quota Used %Used Partition group.foo 600000 358406 60% 38%
The backup volume's name is then the regular name with .backup appended, so the command for group.foo would be:
fs mkmount -dir .backup -vol group.foo.backup
Thanks to Marco for the instructions!