- User Services
- Group Services
- Scientific Computing
- Copy Services
Tape Backups and File Recovery at JLab
The Computing and Networking Infrastructure (CNI) group is committed to providing reliable and redundant backups of all system and user generated data on each of the systems, which it administers. The intent is not only to provide a service to the users who may wish to retrieve archived documents which are no longer stored on primary disk storage but also to prepare for both random mechanical disk failures as well as for the recovery of Jefferson Lab (JLab) work and research in the event of massive physical disaster (i.e. fire, flood, hurricane). Further details on backup procedures and policies can be found on the CNI Backup and Disaster Policy page.
Users are responsible to backup all information not on a disk managed by CNI. This includes all personal computers (PC/PC clones and Macintoshes) as well as workstations not under the aegis of CNI (primarily under the system management of the Accelerator Controls group, Accelerator Division). If important desktop data is saved on the home or group areas (on Windows the J: or M: drives) they will be backed up. We do not back up any individual desktops.
Backups are maintained of the following centrally maintained directories that are provided from central network fileservers: home, group, apps, and site. The scratch, work, and cache directories are not backed up. Detailed information on centrally provided directories can be found on the JLab-CUE Directory Structure page.
If there is a need to recover lost data from CNI managed filesystems or directories there are two possibilities for recovery:
- The data may be located in a snapshot directory that the user may be able to access and recover the files from
- The data may have to be retrieved from CNI tape backups
Snapshot Directory File Retrieval
Files stored on the central fileservers have periodic "snapshots" made of each folder's contents. These snapshots include copies of files as they appeared in the past, and can be used to recover accidentally deleted or changed files without the need to go to tape backups. Every directory on the central fileservers contains a subdirectory named snapshot which itself contains several folders: hourly.0, and hourly.1; or cuehome-Hourly-snapshot_<timestamp>, …. These snapshot directories can be used as a source for copies of files you may have deleted.
NOTE: The /home (J:\) directories are on a new filer. For Windows & Macintosh users, you'll need to follow the *NEW* instructions below for accessing the J:\ (/home) snapshot.
As an example, suppose that you accidentally deleted the file M:\group\yourgroup\myfile on your CUE Windows system. In this case, the folder M:\~snapshot\hourly.0\group\yourgroup\myfile contains your files as they appeared at the last hourly snapshot. The folder M:\~snapshot\hourly.1\group\yourgroup\myfile contains your files from two hours ago, and so on. To restore "myfile", you look in the ~snapshot directories for the one you want and drag it to the original location, perhaps copying M:\~snapshot\hourly.0\group\yourgroup\myfile to M:\group\yourgroup\myfile. You want to copy the file, do not remove it completely from the ~snapshot area.
*NEW* for J:\ (/home):
Traverse directory where myfile existed, in order to restore. Right-click on J:\directoryofmyfile and go to Properties. Click on the Previous Version tab. At this point, you double-click any of the "snapshots" to open. Then, you can copy your file back to your original J:\ directory. You may want to have 2 Windows Explorer windows open.
Another example would be if you had accidentally deleted the file /home/username/myfile on a CUE configured Unix system. In this case the /home/.snapshot/cuehome-Hourly-snapshot_<timestamp>/username/ directory contains your files as they appeared at the last hourly snapshot. The directory /home/.snapshot/cuehome-Hourly-snapshot_<timestamp minus 2 hours>/username/ contains your files from two hours ago, and so on. To restore "myfile" you would search through the .snapshot directories that you want and copy it back to its original location. The process would be as follows:
- Change directories to the directory where the file last resided
- cd .snapshot
- cd cuehome-Hourly-snapshot_<timestamp>
- copy desired file back to its original location or location of your choice.
The file recovery for CUE Macintosh system is very similar to the Windows file recovery. If you accidentally deleted the file smb://jlabhome/home/username/myfile on your Macintosh system. In this case, the folder smb://jlabhome/home/username/.snapshot/cuehome-Hourly-snapshot_<weird timestamp name> contains your files, but you need to select the appropriate timestamp. To restore "myfile", open Finder and open Go menu. Select 'Connect to Server...' and type smb://jlabhome.jlab.org/home/username/.snapshot. Traverse to the place where you last remember having the file or directory. Then, copy the file, do not remove it completely from the .snapshot area.
Since the snapshot directories are maintained by the file servers for you, you cannot copy files into it. It can only be used to retrieve files, as a way to restore file that were accidentally deleted. If you delete a file, and do not notice it for a few days, it will not appear in any of the snapshot folders. If the file is needed, the CNI group can recover it from backup tapes. Be aware that while restoring from the snapshot directory is as fast as copying a file, restoring from tape is not immediate.
Tape Backups File Retrieval
If the files that need to be restored are previous to the copies maintained in the snapshot directories, please email firstname.lastname@example.org to recover the files from tape backup. When submitting a request to recover files, be sure to include the following information:
- last known location of the file
- date of the last known good version of the file
- location to recover the retrieved file into
Please realize that restoration of files from tape is not immediate and can be time intensive.