Users Guide
this association, so you do not want it to change. The issue of SCSI ID assignment is addressed by
persistent binding.
Persistent binding is an HBA function that allows a subset of discovered targets to be bound between a
server and device. Implemented by a worldwide node name (WWNN) or worldwide port name (WWPN),
persistent binding causes a tape drive's WWNN to be bound to a specic SCSI target ID. After a
conguration is set, it survives restarts and any hardware conguration changes because the information
is preserved. If a drive must be replaced, the new drive assumes the WWNN of the old drive because the
WWNN for the drive is location-dependent within the library. Because the WWNN does not change,
persistent binding does not need changing, thus preventing a potential outage.
Chapter 2. Planning 33