In many cases, the use of MPIO for the rootvg creates a situation with dual multi-pathing tools. To simplify system administration and improve system reliability, use DMP to provide multi-pathing for the rootvg.
DMP is supported for the rootvg on vSCSI, NPIV, and physical HBAs. DMP is also supported for alternate root disks and root disks with multiple volumes.
To use DMP on the rootvg, DMP requires a vendor-specific ODM predefined fileset. Veritas includes the predefined filesets for vSCSI devices in the Veritas product distribution. For other devices, obtain and install the ODM predefined fileset from the storage vendor. For example, for the IBM DS array, install the devices.fcp.disk.ibm.rte
fileset.
Rootability is achieved by using the vxdmpadm command, which uses the OS Native stack support feature internally.
# vxdmpadm help native
Manage DMP support for AIX boot volume group(rootvg) Usage: vxdmpadm native { enable | disable } vgname=rootvg vxdmpadm native list [ vgname=rootvg ] vxdmpadm native { release | acquire } [ vgname=rootvg ] where, enable Enable DMP support for AIX boot volume group(rootvg) disable Disable DMP support for AIX boot volume group(rootvg) list List boot paths on which DMP support is enabled release Giveback pvid to OS device paths corresponding to rootvg acquire Takeover pvid from OS device paths corresponding to rootvg
For more information about using DMP with rootvg, see the Dynamic Multi-Pathing Administrator's Guide.