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.