See Using Storage Foundation in the VIO client with virtual SCSI devices

In this release of Storage Foundation, Veritas Dynamic Multi-Pathing (DMP) is enabled on VIO clients by default. After you install or upgrade Storage Foundation in the Virtual IO client, any vSCSI devices are under DMP control. MPIO is disabled.

If you have already installed or upgraded Storage Foundation in the Virtual I/O client, use the following procedure to enable DMP support for vSCSI devices. This procedure is only required if you have previously disabled DMP support for vSCSI devices.

DMP takes control of the devices, for any array that has DMP support to use the array for vSCSI devices. You can add or remove DMP support for vSCSI for arrays.

See Adding and removing DMP support for vSCSI devices for an array