In the case of data loss due to deletion my mistake the more or less classic scenario was to restore the data from backup tape. Since the access to the backup is limited to the root user a support request has to been filed each time.
With the introduction of the new storage system (Server: nas-itet-01) data can be restored from so called snapshots by the owner himself.
Some details about snapshots:
- The snapshots are provided for the last 6 days
- Restoring older data still requires a support request and a restore from tape
- In general a snapshot is taken once per day, approx. between 0:00 and 2:00 am.
- All snapshots have the same file permissions as their original data.
- Snapshot are read-only (NOT writable)
General Info: Backup data on tape are kept for 90 days. Older data can not be restored.
Restore from Linux
In your home a directory called SNAPSHOT provides access to all your personal snapshots.
The available snapshots are named from 0 to 5 with 0 being the newest and 5 the oldest snapshot. The snapshot names are updated in a rotation manner once per day. A further snapshot link is called last and points as the named indicates to the latest (i.e. the newest) snapshot.
A snapshot behaves like a filesystem so you can navigate inside the snapshot by using a shell or your favorite file manager. You can apply most of the linux file tools on the snapshots' content like ls, stat, diff, cp etc.
To restore data from a snapshot simply copy the data from the snapshot to the final destination (i.e. the current filesystem not the snapshot).
Restore from Windows
Use the Windows Explorer and navigate to the file or folder that should be restored (respectively as close as possible if it does not exits anymore) and right-click on it. Click on Properties to open the Properties dialog box. Change to the Previous Version tab and select the version (date of snapshot) you want to restore.
Depending on your needs choose the best option out of 3:
Open: Opens a new Explorer window which can be used to navigate inside the selected snapshot. To restore data simply copy the data from the selected snapshot (using standard Explorer tools) and paste them into the final destination folder, i.e. the current filesystem opened in the old Explorer window (not the snapshot Explorer window)
Copy...: Opens a Windows dialog window to choose the final destination to copy the selected version of the data into. After choosing is made a click on Copy will copy the data into the selected destination.
Restore: Restores the selected version of the data to its original location, i.e the current version will be replaced. A warning message appears. A click on Restore will complete the procedure
For detailed information click on How do I use previous versions? within the Previous Version tab (see picture above)