scsimgr_esdisk.7 (2010 09)

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scsimgr_esdisk(7) scsimgr_esdisk(7)

NAME

scsimgr_esdisk - SCSI class driver esdisk plug-in for scsimgr

DESCRIPTION

The SCSI class driver

esdisk plug-in for scsimgr

implements management and diagnostic operations

speciﬁc to classes of devices bound to the

esdisk driver. esdisk is the native HP-UX SCSI class driver

that handles, by default, all block devices including the following types: direct access, CD/DVD, write-

once read-multiple (WORM), and optical memory (OM).

The plug-in handles the following operations for driver

esdisk:

• Displays and clears driver

esdisk global statistics and the statistics it maintains on instances of

LUNs bound to it, and on related LUN paths.

• Displays status and other information maintained by driver

esdisk on LUNs bound to it.

• Gets, sets, and saves driver

esdisk global, per-lun instance attributes or attributes for a set of dev-

ices bound to the driver.

Commands

The user can explicitly send the following

scsimgr commands to driver esdisk plug-in by specifying

the

-d esdisk option:

clear_stat Clears statistics.

get_attr Displays information on attributes.

get_info Displays status and other information.

get_stat Displays statistics.

save_attr Saves value of attributes in a persistent store.

set_attr Set current values of attributes.

Note: Refer to scsimgr (1M) for the syntax of the above commands.

However, the only instance when it is necessary to explicitly send a command to the plug-in is when per-

forming operations on objects global to driver

esdisk: global statistics, attributes or status information.

In all the other cases, scsimgr automatically invokes the plug-in to perform the driver speciﬁc part of

the operation, when the operation applies to LUNs bound to driver esdisk or to their LUN paths.

Attributes

The following table lists driver

esdisk speciﬁc attributes. Under the category "Device Set", the table

lists which attributes the esdisk driver allows at a settable attribute scope (also known as Device Data

Repository, DDR). Attribute scopes supported by esdisk are peripheral device type (pdt), vendor

identiﬁer (vid), product identiﬁer (pid), and product revision (rev). See attr_scope in scsimgr (1M) for

more information.

Note: The following conventions are used :

• RO is Read Only.

• RW is Read Write.

• uint32 is unsigned 32 bit integer.

• Range of values for applicable attributes is listed.

Object Attribute Name RO/RW Type Description

Version of driver esdisk.Global version RO string

Device capacity in number of blocks.LUN capacity RO uint32

Number of retries for device discovery I/Os dur-

ing Busy or Queue Full condition.

Range: 0 - 0xFFFFFFFF

congest_max_retries RW uint32

Block size in bytes.block_size RO uint32

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (8 pages)

PAGE 1
scsimgr_esdisk(7) scsimgr_esdisk(7) NAME scsimgr_esdisk - SCSI class driver esdisk plug-in for scsimgr DESCRIPTION The SCSI class driver esdisk plug-in for scsimgr implements management and diagnostic operations specific to classes of devices bound to the esdisk driver. esdisk is the native HP-UX SCSI class driver that handles, by default, all block devices including the following types: direct access, CD/DVD, writeonce read-multiple (WORM), and optical memory (OM).
PAGE 2
scsimgr_esdisk(7) A scsimgr_esdisk(7) format_secs RW uint32 Timeout in seconds of SCSI command FORMAT. Range: 0 - 0xFFFFFFFF start_unit_secs RW uint32 Timeout in seconds of SCSI command START UNIT. Range: 0 - 0xFFFFFFFF max_retries RW uint32 Maximum number of I/O retries. Range: 1 - 0xFFFFFFFF path_fail_secs RW uint32 Timeout in seconds before declaring a LUN path offline. Range: 0 - 0xFFFFFFFE esd_secs RW uint32 Maximum time in seconds for the transmission of an I/O.
PAGE 3
scsimgr_esdisk(7) scsimgr_esdisk(7) pref_tport . Indicates whether Asymmetric Logical Unit Access (ALUA) functionality is enabled for the LUN instance. The value of true (1) indicates that ALUA functionality is handled if LUN supports it. The value of false (0) indicates that ALUA functionality is ignored even if LUN supports it.
PAGE 4
scsimgr_esdisk(7) A sA 4 scsimgr_esdisk(7) congest_max_retries RW uint32 Number of retries for device discovery I/Os during Busy or Queue Full condition. Range: 0 - 0xFFFFFFFF format_secs RW uint32 Timeout in seconds of SCSI command FORMAT. Range: 0 - 0xFFFFFFFF start_unit_secs RW uint32 Timeout in seconds of SCSI command START UNIT. Range: 0 - 0xFFFFFFFF max_retries RW uint32 Maximum number of I/O retries.
PAGE 5
scsimgr_esdisk(7) scsimgr_esdisk(7) sistent Reservation ALL: Disable all functions NONE: Enable all functions Enable or disable infinite retries of I/Os May be: true (1): enable false (0): disable infinite_retries _enable RW Boolean retry_delay _enabled RW boolean Enables or disables support of retry delay timer codes returned by devices complying with SAM-4 (SCSI Architecture Model 4), in case of congestion. If set to false (0), retry delay timer codes are ignored.
PAGE 6
scsimgr_esdisk(7) • scsimgr_esdisk(7) least_cmd_load The LUN path with the least number of active I/O requests is selected to execute the next I/O. This policy is appropriate when the paths to the LUN exhibit asymmetric latency characteristics. The load is distributed to optimize the bandwidth on each LUN path. • cl_round_robin (cell aware round robin) This load balancing policy is applicable to HP cell-based platforms.
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scsimgr_esdisk(7) scsimgr_esdisk(7) -a preferred_path=0/3/1/0.0x21000020371972eb.
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(Notes) A (Notes) sA 8 Hewlett-Packard Company −1− HP-UX 11i Version 3: September 2010