You can use the two parameters, devnam_string and wwid_string, with the REPLACE_WWID command to replace a broken tape device with a new device. The command automatically updates the data structures that record the new devnam-WWID correlation, and the device automatically begins to function correctly. This command is useful in two different cases: o In one case, the drive might malfunction and need to be replaced immediately without rebooting the system. If this happens, the drive is physically replaced with a new drive, and the command SYSMAN IO REPLACE_WWID $2$MGAn is issued clusterwide. The /WWID qualifier is not appropriate in this case, because the new WWID is automatically detected using information stored in the device's data structures. o In the other case, the drive might malfunction and not be replaced until after the system has been shut down or rebooted. The device name no longer appears in the SHOW DEVICE display because the device failed to configure during the reboot. The configuration failure occurred either because the broken drive did not respond, or because the new drive has a different WWID from the one SYSMAN IO AUTOCONFIGURE expected at boot time. Therefore, in this situation, in which the device name is in SYS$DEVICES.DAT but not in the SHOW DEVICE display, use the /WWID qualifier to define the new devnam-WWID correlation. Follow these steps clusterwide: 1. Execute the SYSMAN IO LIST_WWID command to display the new WWID. 2. Use the command SYSMAN IO REPLACE_WWID $2$MGAn/WWID=new_ wwid to define the new correlation. 3. Use the SYSMAN IO AUTOCONFIGURE command to configure the device. When you use the SYSMAN IO LIST_WWID command, keep in mind that: o You must set the replacement device to the same SCSI target ID as the original device. o You must stop all activity on the device before issuing the SYSMAN IO REPLACE_WWID command. o The command requires CMKRNL privilege and applies only to FC tapes behind an NSR or MDR.