Configuring the AIX fast fail feature for use with Veritas Volume Manager (VxVM) and Dynamic Multipathing (DMP)

DMP failover takes significant time when the path is disabled from the switch or array side in a SAN environment. This issue is not seen if the path is disabled from the host side. The dynamic tracking and fast fail features of AIX prevent the long failover time.

To configure the AIX fast fail feature for use with VxVM and DMP

  1. Enter the following commands for each Fibre Channel adapter or controller:

    # chdev -l fscsiN -a fc_err_recov=fast_fail -P
    # chdev -l fscsiN -a dyntrk=yes -P

    where N is the number of the controller (0, 1, 2 and so on).

  2. Reboot the system.

  3. Use the lsattr command to verify that the dyntrk and fast_fail attributes are set to True on each adapter, as shown in this example:

    # lsattr -El fscsi0
    attach       switch    How this adapter is CONNECTED      False 
    dyntrk       yes       Dynamic Tracking of FC Devices     True 
    fc_err_recov fast_fail FC Fabric Event Error Recovery Policy True  
    scsi_id      0x10d00   Adapter SCSI ID                    False 
    sw_fc_class  3         FC Class for Fabric controllers.   True