Each medium, be it a tape cartridge or a virtual tape in a VTL, is given a unique label for identification. The label is written to the beginning of a medium during initialization. The media label consists of the pool name (e.g., DAY, WEEK, MONTH) and a five-digit number that is automatically assigned to the respective media of the selected pool by SEP sesam. For example, a tape in the media pool DAY is labelled as DAY00001.
Manually identifying and relabeling tapes
You can check a tape label using the sm_drive info <drive_no.> command or the SEP sesam GUI.
- To check the label using the CLI, set the SEP sesam command environment and enter the command: sm_drive info <drive_no.> In our example, check drive 1: sm_drive info 1 Alternatively, you can also use the sm_sms_interface getlabel command which displays more information about the label (such as the creation date); for details, see FAQ: How can I determine whether a tape is a SEP sesam tape or not? Or, you can check the tape label using the GUI. Depending on your SEP sesam version, proceed as follows:
- In v. < 4.4.3 Beefalo, click on Components -> Drives -> select the drive -> Drive action -> Identify label -> Start.
- In v. ≥ 4.4.3 Beefalo, click on Components -> Loaders -> select the drive within the loader -> Drive Action -> Identify label -> Start.
In the standalone tape drive environment it can happen that multiple tapes are given the same label. This happens because SEP sesam uses the get_oldest strategy to preserve the data on the tapes for the longest possible time. It automatically detects the oldest EOL-free medium and designates the label of the tape to be re-used next, e.g., DAY00004. When an alternate EOL-free tape is already inserted in a single tape drive, SEP sesam checks its label and detects a label mismatch. If the EOL of the inserted tape has not yet expired, SEP sesam will not use the tape. However, if the tape is EOL-free, SEP sesam will initialize it with the original (requested) label, even if it belongs to a different media pool and has its own label, e.g., MONTH00009. In such a case, a tape from another media pool may be accidentally overwritten if it is already EOL-free. This problem occurred in SEP sesam version 220.127.116.11 and was successfully fixed.
Resolving label conflicts
To resolve conflicts with duplicate media labels and avoid problems with potential data loss, you have to manually identify the tape with the original label that was duplicated, insert it into the standalone drive, and relabel it with the original label of the second tape. Then you have to manually replace the stick-on label or the slide-in (insert) label (paper or card) on the front of both tapes. This way you ensure that the newly written backup data is not overwritten.
Example: The label MONTH00009 was overwritten with the label DAY00004.
- Insert the tape that was originally labelled DAY00004 and re-label it to MONTH00009. For details, see above procedure.
- Remove the label DAY00004 from the tape and stick the mismatched label MONTH00009 on it. Then put the label DAY00004 onto the newly written tape (formerly MONTH00009).