Media Position Errors Encountered When Auto Media Verify Is Enabled

When you enable Auto Media Verify for a pool, Backup verifies the data written to volumes from the pool while saving. This is done by reading a record of data written to the media and comparing it to the original record. Media is verified after Backup finishes writing to the volume, which might occur when a volume becomes full or when Backup no longer needs the volume for saving data.

To verify media, nsrmmd must reposition the volume to read previously written data. It does not always succeed in the first attempt. These warning messages appear in the message display in the Backup administration program (nwadmin):

media warning: /dev/rmt2.1 moving: fsr 15: I/O error
media emergency: could not position jupiter.007 to file 44, record
16

No action is required. Backup continues to attempt to find the proper position. If Backup can find the correct position, media verification succeeds and a successful completion message appears.

media info: verification of volume "jupiter.007" volid 30052
succeeded.

In this case, ignore the earlier messages because they only indicate that Backup had problems finding the desired position on the media. If the problem is serious, media verification fails and a subsequent message gives the reason for the failure.