Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

Displaying the I/O policy
To display the current and default settings of the I/O policy for an enclosure, array
or array type, use the vxdmpadm getattr command.
The following example displays the default and current setting of iopolicy for
JBOD disks:
# vxdmpadm getattr enclosure Disk iopolicy
ENCLR_NAME DEFAULT CURRENT
---------------------------------------
Disk MinimumQ Balanced
The next example displays the setting of partitionsize for the enclosure enc0,
on which the balanced I/O policy with a partition size of 2MB has been set:
# vxdmpadm getattr enclosure enc0 partitionsize
ENCLR_NAME DEFAULT CURRENT
---------------------------------------
enc0 1024 2048
Specifying the I/O policy
You can use the vxdmpadm setattr command to change the I/O policy for
distributing I/O load across multiple paths to a disk array or enclosure. You can
set policies for an enclosure (for example, HDS01), for all enclosures of a particular
type (such as HDS), or for all enclosures of a particular array type (such as A/A for
Active/Active, or A/P for Active/Passive).
Warning: Starting with release 4.1 of VxVM, I/O policies are recorded in the file
/etc/vx/dmppolicy.info, and are persistent across reboots of the system.
Do not edit this file yourself.
The following policies may be set:
Administering Dynamic Multi-Pathing
Administering DMP using vxdmpadm
180