A status code 129 in NetBackup means “Disk storage unit is full” (i.e. insufficient disk space).
There are a few things that you can generally do to resolve the problem.
1. Look for duplicate images and when possible delete the copy that resides on disk.
2. Look for expired images that have not yet been cleaned up.
3. If possible, switch the policy for the backup that failed to another storage unit that has sufficient space.
4. Run bpbackup -dssu
