3.1.2 Matrix Server Administration Guide

Chapter 5: Configure the SAN 66

Enable or Disable Failover for a PSD Device

When a failure occurs in the I/O path to a particular PSD device, Matrix

Server by default fails over to another I/O path. You can use this

command to control whether this behavior can occur for specific PSD

devices. (Matrix Server starts with failover enabled.)

# mxmpio enable|disable [<PSD-device ...>]

Specify the Path for I/O

If you are troubleshooting problems with an I/O path, you may want to

direct the I/O to another I/O path. You might also want to manually

balance I/O paths on a per-server basis across the cluster. This is possible

because mxmpio controls are server specific.

You can use the following command to specify either a particular HBA or

a PSD device. Matrix Server will then fail over the I/O to the path that

includes the specified device. In the command, PSD-device is specified by

the base name of the device path, such as psd2p1 (not /dev/psd/psd2p1).

# mxmpio active <target> <PSD-device>

target can be one of the following values:

With the exception of I (the array index), the value specified is converted

to the corresponding host adapter/channel before being used to select the

target.

I A numerical index on the PSD device target array (0..).

M,m A decimal major/minor number identifying the host

adapter.

M:m A hexadecimal major/minor number identifying the host

adapter.

scsiN/C A scsi bus ID. N is the scsi host adapter ID (0..) and C is the

scsi host channel number (0..) as defined in /proc/scsi/scsi

and /proc/scsi/*/[0-9]. If C is omitted, zero is assumed.

sdNsP A device node in /dev. The value is converted to a

major/minor number identifying the corresponding host

adapter.