SVA - Setting the I/O Timer Values for Open Systems Platforms

Asset ID:	1-71-1009879.1
Update Date:	2011-06-01
Keywords:

Solution Type Technical Instruction Sure

Solution 1009879.1 : SVA - Setting the I/O Timer Values for Open Systems Platforms

Applies to:

Sun StorageTek 9393 Shared Virtual Array (SVA)
Sun StorageTek 9500 Shared Virtual Array (SVA)
Sun StorageTek V2X SVA Disk System - Version: Not Applicable to Not Applicable [Release: N/A to N/A]
All Platforms

Goal

Setting the I/O Timer Values for Open Systems Platforms. Please use the following information to change the SCSI time out values (to 270 seconds) on the supported Open System platforms.

Solution

Please use the following information to change the SCSI time out values (to 270 seconds) on the supported Open System platforms. These changes will enhance the recovery of processing jobs/data in the event of a check 0 recovery on the SVA/XSA or other STK/XSA attached products. You will need a system administrator with root login access. All commands to change the time out values to a minimum value of 270 seconds must be made from the root. If any value already exists which exceeds the 270 second minimum limit do not change these values.

HP-UX

There are two commands that can be used to view and change IO timeout parameters on a per device basis. These commands are "pvchange" and "pvdisplay". See the system manual pages for more information on each of these commands.

An example for "pvdisplay" would be:

pvdisplay /dev/dsk/c1t3d0

This will show an IO_time value in seconds which may say default.

To change this value to 270 seconds use the command:

pvchange t 270 /dev/dsk/c1t3d0

The device needs to be part of a volume group before "pvdisplay" and "pvchange" will work. Once the devices are changed to the 270 time out value the host system will need to have a REBOOT to download the changes to the drivers.

RS6000 - AIX

The changes can be made via "smit", via a command line entry or script file using "chdev" to change the time out value and "lsattr" to display the attributes of the devices. The changes can be made upon initial set up to the raw devices or with a system REBOOT to devices already configured to a volume group.

Also if queuing is not turned on request that queuing be turned on to at lease the minimum levels listed below.

SMIT

Devices

Fixed Disk

Change / Show Characteristics of a Disk

Select the hdisk # to change:

Note: If the timeout values are already greater than 270 do not change these values. Also if queuing values are set higher than those listed here no queue value change is needed.

Queue Depth (16)

Queuing TYPE (simple)

Use QERR bit (no)

Device CLEARS its Queue on error (no)

READ/WRITE time out value (270)

START UNIT time out value (270)

REASSIGN time out value (270)

If this is a raw disk you do not need to make any further changes. If this disk is already established in a volume group make the following changes and note that the changes will no be applied until the host system is REBOOT.

Apply change to DATABASE only yes

Via Command Line or you can build a script to include several command lines:

Raw Disk:

Chdev l 'hdisk#' a queue_depth='16' a q_type='simple' a rw_timeout='270' a start_timeout='270' a reassign_to='270' a q_err='no'

Established volume group (REBOOT required):

Chdev l 'hdisk#' a queue_depth='16' a q_type='simple' a rw_timeout='270' a start_timeout='270' a reassign_to='270' a q_err='no' P

SUN

The changes on the Sun are made by editing the '/etc/system' file. Add or modify the following line within this file. Again the value of 270 is a minimum value. If a larger value already exists use the larger value.

set sd:sd_io_time=270

A system REBOOT must occur for this value to take effect. It is suggested that you reboot your system with the following parameters: boot r

D.H. - 12/06/99 - CREATED.

Previously Published As
91092

Change History
Date: 2007-10-05

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