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

147Administering dynamic multipathing (DMP)
Administering DMP using vxdmpadm
Enabling a controller allows a previously disabled path, HBA controller or array port to
accept I/O again. This operation succeeds only if the path, controller or array port is
accessible to the host, and I/O can be performed on it. When connecting Active/Passive
disk arrays, the
enable operation results in failback of I/O to the primary path. The
enable operation can also be used to allow I/O to the controllers on a system board that
was previously detached.
To enable I/O for a path, use the following command:
# vxdmpadm enable path=path_name
To enable I/O for the paths connected to an HBA controller, use the following command:
# vxdmpadm enable ctlr=ctlr_name
To enable I/O for the paths connected to an array port, use one of the following
commands:
# vxdmpadm enable enclr=enclr_name portid=array_port_ID
# vxdmpadm [-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 enable I/O on an array port:
# vxdmpadm enable enclr=HDS9500V0 portid=1A
# vxdmpadm enable pwwn=20:00:00:E0:8B:06:5F:19
Upgrading disk controller firmware
You can upgrade disk controller firmware without performing a system reboot or
unloading the VxVM drivers.
First obtain the appropriate firmware upgrades from your disk drive vendor. You can
usually download the appropriate files and documentation from the vendor’s support
website.
For a system with a volume mirrored across 2 controllers on one HBA, set up the
configuration as follows:
1 Disable the plex that is associated with the disk device:
# /opt/VRTS/bin/vxplex -g diskgroup det plex
2 Stop I/O to all disks through one controller of the HBA:
# /opt/VRTS/bin/vxdmpadm disable ctlr=first_cntlr
For the other controller on the HBA, enter:
# /opt/VRTS/bin/vxdmpadm -f disable ctlr=second_cntlr
3 Upgrade the firmware on those disks for which the controllers have been disabled
using the procedures that you obtained from the disk drive vendor.
4 After doing the upgrade, re-enable all the controllers:
# /opt/VRTS/bin/vxdmpadm enable ctlr=first_cntlr