Preventing tape labels from being overwritten

Tivoli® Storage Manager tape labels can be overwritten by an application that uses a generic or native device driver. If tape labels are overwritten, data can be lost.

About this task

The Tivoli Storage Manager device driver and the Oracle Solaris generic SCSI tape driver (st driver) can coexist in the kernel at the same time. They can also control and operate the same tape device that is attached on the system, which can cause conflicts over how the device is managed.

Note: For Solaris 10 update 10 or higher releases, the SCSI tape driver cannot coexist with the Tivoli Storage Manager driver.

If the Oracle Solaris generic SCSI tape driver (st driver) controls devices that are also used by the Tivoli Storage Manager device driver or the IBMtape device driver, Tivoli Storage Manager internal tape labels can be overwritten and data can be lost. By default, the st driver rewinds tapes at the end of an operation unless the non-rewind option is specified in the device special file name.

The auto rewind operation relocates the tape header position to the beginning of the tape. If the tape remains loaded in the drive, the next non-Tivoli Storage Manager write operation overwrites the Tivoli Storage Manager tape label because the label is at the beginning of the tape.

To prevent Tivoli Storage Manager data from being overwritten, the rmstdev utility locates and deletes all device special files that are created by the st driver and that correspond to devices configured by either the Tivoli Storage Manager device driver or the IBMtape device driver. This utility runs at startup when the server or storage agent is started automatically. If you do not start the Tivoli Storage Manager server or storage agent automatically, run rmstdev -d as the root user before you start the server or storage agent.

If rmstdev does not run when the server is started and st device special files are detected for any Tivoli Storage Manager tape drives, the drives are put into the polling state and the following error message is issued every 10 minutes:

The server has detected that <tape drive> can also be accessed by other applications
through the st device special file <device special file name>. You must run the 
rmstdev utility with -d as the root user to delete the st device special file.

After one hour, the drive is taken offline if the problem still exists.

Error messages are also displayed when the DEFINE PATH command is issued and Tivoli Storage Manager detects st device special files. The operation fails and the drive is not defined. To prevent any conflict that can occur, log on as the root user and run /opt/tivoli/tsm/server/bin/rmstdev -d to delete the st special files. You do not have to halt the server to run the rmstdev utility. You can then redefine a path to the drive.