The VCR data on the volume is lost or corrupted, resulting in degraded tape positioning. The mount fails because the tape drive was configured to fail mounts that indicate this condition.
The client command fails and the transaction is rolled back.
Until the VCR data can be restored, the user can issue the UPDATE VOLUME command to make the volume unavailable. There are two methods to restore the VCR data. The first method uses the MOVE DATA command to move the data off the tape and to return the tape to scratch or empty status. The VCR data is rebuilt when the empty tape is rewritten from the beginning-of-tape. The second method rebuilds the VCR by loading the tape and locating directly to the end-of-data. This is done by the server in normal use whenever data is appended to the end of the tape. It can also be done independent of the server by loading the tape in an unused drive and using the tapeutil program. Select the tapeutil option "Space to End-of-Data".