Solaris SAN Configuration and Multipathing Guide

To Configure Auto-Failback for a Particular Multipathing Support

Symmetrical devices allow for automatic failback to a possible optimal path. If a failover occurs on the initial path, the standby path becomes the new online path. Usually the standby path is a suboptimal path. When auto-failback is enabled, the initial path comes back online, failover to the initial path automatically occurs.

Run the mpathadm list mpath-support command.

# mpathadm list mpath-support
mpath-support: libmpscsi_vhci.so

Select an mpath support name from the output list.

Run the mpathadm modify mpath-support -a [on | off] mpath-support-name command.
# mpathadm modify mpath-support -a off libmpscsi_vhci.so

Run the mpathadm show mpath-support mpath-support-name command to check the change.

# mpathadm show mpath-support libmpscsi_vhci.so
mpath-support: libmpscsi_vhci.so
     Vendor: Sun Microsystems
     Driver Name:  scsi_vhci
     Default Load Balance:  round-robin
     Supported Load Balance Types:
          round-robin
          logical-block
     Allows To Activate Target Port Group Access:  yes
     Allows path Override:  no
     Supported Auto Failback Config: yes
     Auto Failback:  on
     Failback Polling Rate (current/max):  0/0
     Supported Auto Probing config: no
     Auto Probing:  NA
     probing Polling Rate (current/max):  NA/NA
     Supported Devices:
          Vendor:  SUN
          Product:  T300
          Revision:
          Supported Load Balance Types:
               round-robin
          Vendor:  SUN
          Product:  T4
          Revision:
          Supported Load Balance Types:
               round-robin

Note –

The auto-failback display initiated by the mpathadm modify command setting is effective while the system is running. However, to keep the changed setting persistent, you must update the /kernel/drv/scsi_vhci.conf file. Refer to Configuring Automatic Failback.