You can use the command-line interface (CLI) to record
a change to a defined host object.
Before you begin
Because it is sometimes necessary to replace the host-bus
adapter (HBA) that connects the host to the SAN, you must inform the
system of the new worldwide port names (WWPNs) that this HBA contains.
Ensure
that your switch is zoned correctly.
Procedure
To inform the system of a change to a
defined host object, complete the following steps.
- Issue this CLI command
to list the candidate HBA ports:
lsfcportcandidate
orlssasportcandidate
You will
see a list of the HBA ports that are available for addition to host objects. One or more of these
HBA ports will correspond with the one or more WWPNs that belong to the new HBA port.
- Locate the host object that corresponds
with the host in which you have replaced the HBA. The following CLI
command lists all the defined host objects:
lshost
- Issue the following CLI command to list the WWPNs that are currently
assigned to the host object:
lshost hostobjectname
where hostobjectname is the name of the host object.
- Issue the following CLI command to
add the new ports to the existing host object:
addhostport -fcwwpn one or more existing port names
separated by : hostobjectname/ID
where one or more existing port names separated by : is the WWPNs that are
currently assigned to the host object and hostobjectname/ID is the name or ID of
the host object.
- Issue the following CLI command to
remove the old ports from the host object:
rmhostport -fcwwpn one or more existing port names
separated by : hostobjectname/ID
where one or more existing WWPNs separated by a colon (
:) are the WWPNs that are
currently assigned to the host object and
hostobjectname/ID is the name or ID of
the host object.
Note: When volume protection is enabled for the system, the
deletion of the specified host port fails if the following conditions are met:
- It is the last active port on the host.
- It is mapped to any volume that has received I/O within the specified volume protection
interval.
If volume protection is enabled, and the host port being deleted is the last port for a host
which is mapped to any volume which has received I/O within the defined volume protection time
period, then the command will be failed. If multiple hosts are mapped to the same active volume, the
system deletes the port if the host is offline.
Results
Any mappings that exist between the host object and the volumes
are automatically applied to the new
WWPNs. Therefore,
the host sees the volumes as the same SCSI LUNs as before.
What to do next
See the
IBM®
System
Storage
Multipath Subsystem Device
Driver User's
Guide or the documentation
that is provided with your multipathing driver for additional information
about dynamic reconfiguration.