Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

146 Administering dynamic multipathing (DMP)
Administering DMP using vxdmpadm
The enclosure can be returned to the single active I/O policy by entering the following
command:
# vxdmpadm setattr enclosure ENC0 iopolicy=singleactive
Disabling I/O for paths, controllers or array ports
Note: From release 5.0 of VxVM, this operation is supported for controllers that are used
to access disk arrays on which cluster-shareable disk groups are configured.
Disabling I/O through a path, HBA controller or array port prevents DMP from issuing
I/O requests through the specified path, or the paths that are connected to the specified
controller or array port. The command blocks until all pending I/O requests issued through
the paths are completed.
To disable I/O for a path, use the following command:
# vxdmpadm [-c|-f] disable path=path_name
To disable I/O for the paths connected to an HBA controller, use the following command:
# vxdmpadm [-c|-f] disable ctlr=ctlr_name
To disable I/O for the paths connected to an array port, use one of the following
commands:
# vxdmpadm [-c|-f] disable enclr=enclr_name portid=array_port_ID
# vxdmpadm [-c|-f] disable pwwn=array_port_WWN
where the array port is specified either by the enclosure name and the array port ID, or by
the array port’s worldwide name (WWN) identifier.
The following are examples of using the command to disable I/O on an array port:
# vxdmpadm disable enclr=HDS9500V0 portid=1A
# vxdmpadm disable pwwn=20:00:00:E0:8B:06:5F:19
You can use the -c option to check if there is only a single active path to the disk. If so, the
disable command fails with an error message unless you use the -f option to forcibly
disable the path.
The disable operation fails if it is issued to a controller that is connected to the root disk
through a single path, and there are no root disk mirrors configured on alternate paths. If
such mirrors exist, the command succeeds.
Enabling I/O for paths, controllers or array ports
Note: This operation is not supported for controllers that are used to access disk arrays on
which cluster-shareable disk groups are configured.