File Recovery at Jefferson Lab

If there is a need to recover lost data from IT Division managed filesystems or directories there are two possibilities for recovery:

  1. The data may be located in a snapshot directory that the user may be able to access and recover the files from
  2. The data may have to be retrieved from Tape Backups managed by the Computing Network and Infrastructure (CNI) group within the IT Division

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.

 

Windows

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.  This works for the J drive (home), M drive (sgroup) and O drive (group).

Unix

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:

  1. Change directories to the directory where the file last resided
  2. cd .snapshot
  3. cd cuehome-Hourly-snapshot_<timestamp>
  4. copy desired file back to its original location or location of your choice.

Macintosh

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 contact the IT Division Help Desk to recover the files from Tape Backups. 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.

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