Summary
With reserve and release on Netware, backups do not run locally to the appropriate SAN device server because the operating system did not load the device driver for the tape drive. This frequently occurs when machines are rebooted.
Resolution
This problem must be solved through administrative means and is an unfortunate byproduct of the reserve/release software solution. This problem applies to an environment with Netware and SAN support for DPX. In this example, suppose we have two Netware servers on the SAN, node A and node B, and a single tape drive. When node A is running a backup and has a reserve on the tape drive, and node B restarts, the tape drive will be listed as an unbound device on node B after startup. This is because the tape drive will not respond to a SCSI mod sense during reservation and the device driver cannot bind to the tape drive as a result.
In addition, the tape mount manager (SSTPTMM.NLM) will cache available SAN device paths on startup. If the device drivers are not loaded, no entry will be put into the tape mount manager cache. In this case, the SAN path will not be reused until the tape mount manager is unloaded, even after performing a scan for new devices and reloading the device driver. In this case, the best solution is to stop/start DPX to clear the condition.