Making SAN changes on IBM Power Systems hosts running AIX

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You can change the storage area network (SAN) configuration on an IBM® Power Systems host.

Before you begin

Before you make a SAN configuration change, ensure that AIX® Dynamic Tracking is enabled for the Fibre Channel adapter. Dynamic Tracking enables AIX to detect changes in the Fibre Channel N_Port ID of the DS8000® and adjust I/O traffic as needed. Examples of SAN configuration changes are changing the switch port that is connected to the storage system or rebooting a switch.

To determine whether Dynamic Tracking is enabled on a Fibre Channel adapter:

  1. Enter lsattr –El fscsiX where fscsiX is the FC SCSI I/O Controller Protocol Device that corresponds to the Fibre Channel adapter attached to the DS8000.
  2. If the attribute dyntrk has a value of no, Dynamic Tracking of Fibre Channel devices is not enabled for this FC adapter. To enable Dynamic Tracking, enter chdev –l fscsiX –a dyntrk=yes
Notes:
  1. You might need to unconfigure the Fibre Channel adapter to change the value of the dyntrk attribute. Complete the following procedure to unconfigure a Fibre Channel adapter. Alternatively, it is possible to use the –P option on the chdev command and then reboot the partition for the new dyntrk attribute value to take effect.
  2. For a complete overview of AIX Dynamic Tracking of Fibre Channel device capabilities on IBM Power Systems see the https://www.ibm.com/support/knowledgecenter/ssw_aix.

About this task

You can modify the following steps, depending on the software stack on the AIX that is using the DS8000.

Procedure

To unconfigure the Fibre Channel adapter when used in a typical AIX configuration, complete the following steps.

  1. Stop all I/O that is running to the affected disks.
  2. For each host that is connected to the storage system, enter umount filesystem_name for all file systems to be unmounted.
  3. Enter varyoffvg VG_name for each 2107/242x/533x volume group to be varied offline.
  4. Enter rmdev -dl fcsadapter_number -R to remove the Fibre Channel adapter.
    The value of adapter_number is the number of the Fibre Channel adapter that you want to remove, for example, rmdev -dl fcs1 -R.
  5. Make all required SAN changes.
  6. Enter cfgmgr to reconfigure the adapter and rediscover the 2107/242x/533x hdisks.
  7. Enter varyonvg VG_name for each 2107/242x/533x volume group to be varied online.
  8. Enter mount filesystem_name to remount all file systems from all hosts that are connected to the storage system.
  9. Resume I/O to the affected disks.