Details
Regular backups are made of the public Linux systems of Academic Computing, which include the AFS file servers and all of the central systems.
These backups are designed to protect against hardware failures and short-term emergencies only. They are not permanent archives. If you need to restore lost files, you should seek help promptly while the backups are still available. Backup tapes are overwritten once they expire. The backup scheme used for the AFS file servers and local disks are slightly different. Most user files are stored in AFS.
- All Files (Local Disk and AFS Files)
- AFS Files
- Timing
To restore a file:
All Files (Local Disk and AFS Files)
All files, whether local to a single computer or in the AFS system (visible to all of the computers), are backed up using the following general scheme:
- A full monthly backup of the data, saved for 12 months.
- A daily incremental backup, kept for 31 days.
Files can be restored to the state they were in at any daily backup for the past 31 days and to any monthly backup from the past year. Files of users who have left and been removed from the system can be recovered for up to one year.
AFS Files
ALL files in AFS, including user home directories and RStor data volumes, have an additional daily snapshot facility.
- A complete "snapshot" of the directory as it exists at midnight. These daily snapshots are kept online until overwritten by the next one. If you accidentally delete a file, the most recent backup can be retrieved trivially, as long as you realize and seek assistance before it gets overwritten at midnight. Retrieving files from yesterday's snapshot can be performed without administrator assistance.
- The snapshots can be found (Readonly) at:
/afs/northstar.dartmouth.edu/users/m/_yesterday/myusername
or
\\afs\northstar.dartmouth.edu\users\m\_yesterday\myusername
Substitute your AFS account name for 'myusername', and the first letter of your name for '/m/'
Timing
The exact time of the backups may be important to know when determining which files to restore. This may change; consult with the system administrators for the latest information. As of March 2012:
- All AFS backups are made from snapshots taken each midnight.
- The AFS monthly backups are taken on the first Wednesday of the month.
- Local daily backups start at 19:00.
- Local monthly full backups are made on Saturdays starting at 18:00. The first Saturday of the month is saved as the "monthly" backup.