3.7.0 HP StorageWorks HP Scalable NAS File Serving Software administration guide - HP Scalable NAS 3.7 for Linux (AG513-96002, October 2009)

Shows the load for each target (SCSI command I/Os) and total for the PSD
device (block layer I/Os), number of failovers, and fatal errors for each device.
iostat [-u] [interval [count]] [<psddev> ...]
Show general I/O statistics for each device.
rawstat [interval [count]] [<psddev> ...]
Dump general I/O statistics for each device in a raw format.
Enable or disable failover for a server
A cluster server can use multiple FC ports to connect to the Fibre Channel fabric. If
the FC port or FC switch currently being used for I/O should fail, HP Scalable NAS
will by default fail over the I/O to another FC port/FC switch path.
You can use the following command to control whether this failover behavior can
occur on a particular node. Run the command on the server where you want to
change the failover behavior. (HP Scalable NAS starts with failover enabled.)
# mxmpio enableall|disableall
Enable or disable failover for a PSD device
When a failure occurs in the I/O path to a particular PSD device, HP Scalable NAS
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. (HP Scalable NAS starts
with failover enabled.)
# mxmpio enable|disable [<psddev ...>]
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. HP Scalable NAS 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> <psddev>
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