Configuring kernel SCSI parameters on an HP AlphaServer Tru64 UNIX host system

This section describes how to set up and configure the Tru64 Unix device parameter database.

This procedure applies to all versions of Tru64 Unix 4.0f and later. See the Tru64 Unix man files for ddr.dbase and ddr_config for more information.

With the storage quiesced, the host system in single-user mode, and logged in to the host system with root privileges, edit the /etc/ddr.dbase file, and include the following parameter values in the DISKS subsection.

Table 1 provides the recommended settings for the DS6000™ SCSI device.

Table 1. Recommended settings for the SCSI DEVICE.
Parameters	Recommended settings
TypeSubClass	hard_disk, raid
BadBlockRecovery	disabled
DynamicGeometry	true
LongTimeoutRetry	enabled
TagQueueDepth	20
ReadyTimeSeconds	180
CMD_Write_Verify	supported
InquiryLength	255
RequestSenseLength	255

Compile by executing the following command: ddr_config -c .
Confirm that the values were included by issuing the following command: ddr_config -s disk IBM 1750 .
Edit the /sys/data/cam_data.c. file to change the nonread/write command timeout values in the changeable disk driver timeout section from 10 seconds to 60. Locate the existing timeout value u_long cdisk_to_def = 10; /10* seconds */, and change the value to u_long cdisk_to_def = 60; /60* seconds */.
Compile cam_data.c by issuing the following command: doconfig -c HOSTNAME, where HOSTNAME is the name of the system kernel. It can be found in the /sys/conf/ directory.

Figure 1 provides example output from the doconfig command.

Figure 1. Example of the doconfig command

#doconfig -c ES47 
*** KERNEL CONFIGURATION AND BUILD PROCEDURE ***

Saving /sys/conf/ES47 as /sys/conf/ES47.bck

Do you want to edit the configuration file? (y/n) [n]: y

Using ed to edit the configuration file.  Press return when ready,
or type 'quit' to skip the editing session: quit


*** PERFORMING KERNEL BUILD ***
Working....Wed Mar 22 17:36:19 PST 2006

The new kernel is /sys/ES47/vmunix
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