Installation and Reference Guide for HP MPIO Full Featured DSM for XP family of Disk Arrays 3.00.00 (AA-RVJ6F-TE, March 2008)

The hpdsm set device policy command sets the load balancing policy for device x or for all

devices, depending on the input parameter speciﬁed, to one of the following:

• No_Load_Balance (NL B) – All I/O requests are routed through a chosen active path.

• Round_Robin (RR) – All I/O requests are d istributed across all active paths to the device in a

round robin manner.

• Shortest_Queue_Requests (SQR) – Each I/O request is routed to the active path with the least

number of outstanding requests.

• Shortest_Queue_Bytes (SQB) – Each I/O request is routed to the active path with the least number

of outstanding data bytes.

• Shortest_Queue_ServiceTime (SQST) – Each I/O request is routed to the active path where the

total outstanding time for pending I/O requests is the least.

The example below demonstrates the i nformation displayed by the hpdsm set device policy

command.

NOTE:

You cannot change the load balance policy for the devices using SCSI-2 reservations in an MSCS

environment.

Example:

hpdsm set device=1 policy=sqst

Device Name : HP OPEN-K*2

Device Serial No. : 040076E1000A

Change Load Balance policy (y/n)? y

Load Balance policy changed. Verify by issuing "hpdsm devices" command.

Example:

hpdsm set device=all policy=rr

Successful for all the devices. Verify by issuing "hpdsm devices" command.

hpdsm set device path

Syntax: hpdsm set device=1 path=1

The hpdsm set device path command changes the preferred path for device x asshowninthe

example below.

NOTE:

Use the hpdsm paths device command to view the available paths for the device.

HP MPIO Full Featured DSM for XP family of Disk Arrays 3.00.00