Name:Value Pair Format to Tune Disk Drivers - Managing SAN Devices and I/O Multipathing in Oracle® Solaris 11.4

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`Name`:`Value` Pair Format to Tune Disk Drivers

The sd and ssd drivers support the JSON-text name:value format, which enables you to set specific tunable property values.

Use the following syntax for an sd driver:

sd-config-list = duplet [, duplet]*;

Note - Be sure to end the entry with a semicolon or the configuration will be invalid and the properties will retain their default values.

Use the following syntax for an ssd driver:

ssd-config-list = duplet [, duplet]*;

where, duplet is "VIDPID", "tunable [, tunable]*"

VID: Content of the vendor identification (VID) field of the device response to a SCSI INQUIRY command. The VID field must be eight characters in length. If the VID field is less than eight characters, you must add whitespaces to make the length of the VID to eight characters. See Example 13, Configuring Two Target Devices in an sd.conf File.
PID: Content of the product identification (PID) field of the device response to a SCSI INQUIRY command. The PID can contain a maximum of 16 left-adjusted characters. If you provide less than 16 characters, then the comparison is limited to the length of the PID that you have provided.
tunable[, tunable] *: tunable is the name:value pair.

Note - If you misspell a tunable or do not end the entry with a semicolon, the configuration is invalid and the device properties will retain their default values.

The PID value is considered a match when the prefix value returned by the SCSI INQUIRY command and the PID in the sd-config-list or ssd-config-list are same. For example, if CMS200 is the PID in the sd-config-list or ssd-config-list entry and if the PID returned by the SCSI INQUIRY command is CMS200-R, CMS200-T, or CMS200-UV10 would all be considered a match.

On a SPARC platform, the target devices can be bound to sd or ssd driver depending on whether the device is an FC device and whether I/O multipathing is enabled on the device. You can use the prtconf command to check the device configuration information. See the prtconf(8) man page.

Example 13 Configuring Two Target Devices in an sd.conf File

The following example shows how to configure two target devices SAMPLE and SUM in an sd.conf file.

sd-config-list = "SAMPLE  STTU1234566AB", "delay-busy:6000000000", 
                 "SUM     ABC200_R", "retries-busy:5, throttle-max:300";

In this example, for the device SAMPLE, the VID is SAMPLE and the PID is STTU1234566AB. The delay time before retrying is set to 6 seconds.

For the device SUM, the VID is SUM and the PID is ABC200_R. The number of retries on an I/O busy status is set to 5. The maximum throttle value is set to 300.

Example 14 Configuring Two Target Devices in an ssd.conf File

The following example shows how to configure two target devices GATES and SINE in an ssd.conf file.

ssd-config-list = "GATES   AB568536611CD46G", "reset-lun:TRUE", 
                  "SINE    XYZ200_R", "retries-notready:6, throttle-min:200";

In this example, for the device GATES, the VID is GATES and the PID is AB568536611CD46G. The value TRUE for the reset-lun tunable parameter indicates that the LUN is reset.

For the device SINE, the VID is SINE and the PID is XYZ200_R. The number of retries when the I/O is not ready is set to 6. The minimum throttle value is set to 200.