Self-Service File Recovery

Intro

We have the capacity for you to recover old versions of changed or deleted files yourself, from our online backups. If the the below instructions don't work, please see Requesting Restoration of a Deleted File.

How to Restore a File

  • Go to the appropriate backups directory for the system.
    • For grad net Linux clients, the directory is /users/backups .
    • For ugrad net Linux clients, the directory is /home/backups .
    • For the Grad Net Static Datashare, the directory is /static/backups .
  • Each subdirectory in that directory is a separate backup; the name of the subdirectory gives the date and time the backup was made. (e.g. 2019-09-16-102500 contains a backup made at 10:25 am on Monday, September 16th, 2019.)
    • It might take a while (several minutes in some cases) to list all of the backups currently available.
  • Go into the directory containing the backup you want to use.
  • The backup contains a complete copy of all of our home directories; go into yours (it should match your account name).
  • From here, find the file or files you want to restore.
  • Copy the files from the backup into your own home directory.

If You're Not Sure Which Backup to Use

From a shell, you can use wildcards in /users/backups for CS Grad accounts and /home/backups for CS Ugrad accounts to look at all of the backups of a particular file at once.

For example, if your account name is account on the CS Grad Net and you realize you accidentally deleted a file named example.c from your homework directory, you could run these commands in a terminal: 

cd /users/backups
ls -l */account/homework/example.c

This will take a little while to finish—it takes time to access each backup in turn—and it might give output looking something like this: 

...
-rw-r--r--. 1 account users 848 Apr 15  2019 2019-09-16-000000/account/homework/example.c
-rw-r--r--. 1 account users 848 Apr 15  2019 2019-09-16-040000/account/homework/example.c
-rw-r--r--. 1 account users 848 Apr 15  2019 2019-09-16-080000/account/homework/example.c
-rw-r--r--. 1 account users 848 Apr 15  2019 2019-09-16-120000/account/homework/example.c
-rw-r--r--. 1 account users 848 Apr 15  2019 2019-09-16-160000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-16-200000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-17-000000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-17-040000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-17-080000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-17-120000/account/homework/example.c
-rw-r--r--. 1 account users 850 Sep 16 16:58 2019-09-17-160000/account/homework/example.c

If the output ended there, you can see that the file was modified on September 16th and, if there are backups more recent than 4pm on September 17th, deleted on the 17th. You could use the 2019-09-17-160000 backup to get the file as it existed shortly before it was deleted, or you could use the 2019-09-16-160000 backup to get the file as it was before it was changed on the 16th.

Backup Availability

We make online backups of all of our files every five minutes. Most of those backups are only kept for a few hours. (If we kept them indefinitely, we'd run out of storage space very quickly!) Some, however, are kept for days, weeks, months, and even years.

In general, the further back in time you go, the further apart our online backups are. If you need a file that was deleted an hour ago, you might be able to choose from backups that are just minutes apart from each other. If, on the other hand, you need a file that was deleted a year ago, you might have to choose among backups that are weeks apart.

Our offline backups operate a different rate from the online ones, so if there's a file you can't recover from the online backups, you can contact us to request restoration and we'll see if it's available in the offline backups.