DISK¶

DISK Displays information about the disks in the system.

This command is used to change the configuration settings for the disks in the system and monitor the status of the disk channels. The command will display the current disk configuration settings and the status of each disk channel. The INFO= parameter can be used to display all of the information about a disk in the system. The LIST parameter will display a list of the disks installed in the system and indicate how many were found.

AGINGLIMIT=x|OFF

Sets the maximum time a command should wait in the disk command queue for. This parameter is for Hitachi SAS drives only. Each unit of this timer is 50 ms, where 0 is 50 ms. Range: 0 to 4 (50 to 250 milliseconds) or OFF. Default is 3, (200 milliseconds)

AUTOREASSIGN=ON|OFF

Allows the user to turn on or off whether bad blocks will be reassigned when a medium error occurs on a healthy tier. Default is ON.

CMD_TIMEOUT=x

This parameter sets the retry disk timeout (in seconds) for an I/O request. The retry timeout value indicates the maximum amount of time that is allotted to receive a reply for each retry of an I/O request. If the I/O request does not complete within this time, it is aborted and potentially retried: if there is still time remaining in the overall disk timeout to allow for another retry, it is retried; if not, it completes with an error status. This parameter must be smaller than or equal to TIMEOUT. Valid range is 1 to 512 seconds. Recommended value for SAS drives is 11 seconds. Recommended value for SATA drives is 31 seconds. Setting the timeout below the recommended values can cause disk failures. Default is 31 seconds.

DEFECTLIST[=tc]

Allows the user to display the number of defects in the defect list for the specified disk. The defect list contains all the physical sectors on the disk that the drive has identified as bad, and to which the disk’s hardware prevents access. The list is classified into two types: the permanent list and the grown list. The permanent list consists of the bad sectors that are identified by the disk manufacturer; the grown list consists of the bad sectors that are found after the disk has left the factory (and which can be added to at any time). The disk is specified by its tier and channel locations, ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>.

DIAG[=tc]

Performs a series of diagnostics tests on the specified disk. The disk is specified by its physical tier and channel locations, ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>.

FAIL[=tc]

This parameter tells the system to fail the specified disk at the physical tier and channel locations indicated by ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>. When a non-SPARE disk is specified: If failing the disk won’t cause a multi-channel failure, the disk is marked as failed, and an attempt is made to replace it with a spare disk. When a SPARE disk is specified: If the spare disk is currently in use as a replacement for a failed disk, then the disk that the spare is replacing is put back to a failed status, and the spare is released, but it is marked as unhealthy and unavailable.

FAST_FAIL=[ON|OFF]

This parameter turns on/off the fast fail mode for disks that are slow to respond to data access commands. The fast fail parameters can be customized to a particular need. Default is OFF.

FAST_FAIL_THRESHOLD=’num cmds’

This parameter indicates how many consecutive commands in the fast fail algorithm must occur before failing the drive for this reason. The default value is 5. Valid range = 2 - 20.

FAST_FAIL_WINDOW_END=’t’

This parameter indicates the timeout in seconds for when a disk response is received outside of a window in the future. If the command finishes outside of this time value, it is not aggregated in the slow disk algorithm as it is considered a separate instance of the event and the counter will restart. The default value is 90 seconds. Valid range = 3 - 180.

FAST_FAIL_WINDOW_START=’t’

This parameter indicates the timeout in seconds for when a disk response is considered slow and will count against the drive in the slow disk fail algorithm. The default value is 5 seconds. Valid range = 2 - 179.

INFO[=tc]

This parameter displays the information and status about a specific disk in the system. The disk is specified by its physical tier and channel locations, ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>.

LIST[=SAS_ID|SPEED]

This parameter displays a list of all the disks installed in the system and indicates how many were found of each type. The optional SAS_ID parameter will display the SAS ID of the device instead of the serial number. The optional SPEED parameter will display the link speed of the device instead of the RPM.

LLFORMAT[=tc]

Allows the user to perform a low level format of a disk drive. The disk is specified by its tier and channel locations, ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>.

MAXCMDS=x

Sets the maximum command queue depth to a tier of disks. Range: 1 to 32 commands per tier. Default: 16 commands. Setting should be as follows: - 16 if any SATA drives are used. - 32 for everything else.

MAXREADLEN=x

Sets the maximum read command length for SATA drives in KiB. This parameter is used to increase throughput on systems with a large number of SATA tiers by reducing the contention for the SAS lanes. 128K is the recommended setting for systems with 16 tiers or more of SATA disks. 2048K is the recommended setting for systems with SAS disks. Range is 128 to 2048. Default is 128.

MAXWRITELEN=x

Sets the maximum write command length to the drives in KiB. This parameter is provided for testing only and should normally not be changed. Range is 128 to 2048. Default is 2048.

PLS[=[t][c]]

Requests/displays the PHY Link Error Status Block information for the specified drive. Note that SATA and SAS drives report PHY errors differently. The PHY information consists of the following items:

ERROR	SATA AAMUX PHY ERRORS Explanation
H-RX	Number of SATA FIS CRC errors received on the host port of the AAMUX
H-TX	Number of SATA R_ERR primitives received on the host port indicating a problem with the transmitter of the AAMUX
H-Link	Number of times the PHY has lost link on the host port
H-Disp	Number of frame errors for the host port of the AAMUX. These include: code error, disparity error, or realignment
O-RX	Number of SATA FIS CRC errors received on the other host port of the AAMUX
O-TX	Number of SATA R_ERR primitives received on the other host port indicating a problem with the transmitter if the AAMUX
O-Link	Number of times the PHY has lost link on the other host port
O-Disp	Number of frame errors for the other host port of the AAMUX. These include: code error, disparity error, or realignment
D-RX	Number of SATA FIS CRC errors received on the device port of the AAMUX
D-TX	Number of SATA R_ERR primitives received on the device port indicating a problem with the transmitter of the AAMUX
D-Link	Number of times the PHY has lost link on the device port
D-Disp	Number of frame errors for the device port of the AAMUX. These include: code error, disparity error, or realignment

Error	SAS PHY ERRORS Explanation
InvDW	Invalid DWORD Count - The number of invalid dwords received outside of the PHY reset sequence.
RunDis	Running disparity Count - The number of dwords containing running disparity errors received outside of the PHY reset sequence.
LDWSYN	Loss of DWORD synchronization count - The number of times the PHY has lost synchronization and the link reset sequence.
PHYRES	PHY Reset Problem count - The number of times the PHY reset sequence has failed.

The disk is specified by its physical tier and channel locations, ‘tc’,where:

‘t’ indicates the tier in the range <1..128>, and
‘c’ indicates the channel in the range <ABCDEFGHPS>.

If neither the tier nor the channel are specified, the PLS information is requested from all drives. If only the tier is specified, the PLS information is requested from all the drives on the specified tier.

PMBIT=ON|OFF

When ON this parameter sets the PM (performance mode) bit in Seagate SAS drives mode pages. When OFF the Seagate drive uses its default performance mode settings. Default is OFF.

QUARANTINE

Displays the of number quarantine events on this controller for each disk in the system. Only tiers with quarantine counts will be displayed. Use QUARANTINECLEAR to reset the quarantine counts.

QUARANTINE=[ON|OFF]

Enables/disables the disk quarantine feature for all of the disks. A disk cannot be quarantined unless FASTAV is enabled for the LUN. Default is OFF.

QUARANTINECLEAR

Resets the quarantine counts for all of the disks.

QUARANTINECMDLIMIT=x

Sets the maximum number of outstanding disk commands after a good response before a quarantined disk can be put back into service. Range 0 to 32 where 0 indicates no delay before putting the disk back into service. Default is 0.

QUARANTINETIMEOUT=x

Sets the minimum timeout before a disk can be quarantined in 16.6 millisecond increments. A disk cannot be quarantined unless FASTAV is enabled and has timed out on the command. Range 6 to 65535. Default is 12 (200 milliseconds)

REASSIGN[=tc] [0xh

Allows for the reassigning of defective logical blocks on a disk to an area of the disk reserved for this purpose. The disk is specified by its tier and channel locations, ‘tc’, where: ‘t’ indicates the tier in the range <1..128>, and ‘c’ indicates the channel in the range <ABCDEFGHPS>. 0xh is the hexadecimal value of the LBA (Logical Block Address) to be reassigned.

REBUILD[=tc]|ALL

This parameter tells the system to start a rebuild operation on a (presumably) already failed disk. A rebuild operation restores a failed disk to a healthy status once it completes. Note that this operation can take several hours to complete depending on the size of the disk and the speed of the rebuild operation. The speed of the rebuild operation can be adjusted with the DELAY and EXTENT parameters of the TIER command. In addition, the rebuild operation can be stopped, or paused and resumed with the TIER STOP, TIER PAUSE, and TIER RESUME commands. The TIER AUTOREBUILD command can be used to automate the rebuild process. Note that SPARE disks are handled slightly differently from other disks, in that SPARES that are not in use as an active replacement for a failed disk elsewhere in the system are simply returned to a normal healthy status by this command; SPAREs that are in use are already considered healthy and are not rebuilt. The failed disk to be rebuilt is specified by its physical tier and channel locations, ‘tc’, where:

‘t’ indicates the tier in the range <1..128>, and
‘c’ indicates the channel in the range <ABCDEFGHPS>.

All failed and replaced disks can be rebuilt using the ALL parameter.

REBUILDNOJOURNAL[=tc]|ALL

This parameter tells the system to start a rebuild operation on a (presumably) already failed disk without using the journal. A rebuild operation restores a failed disk to a healthy status once it completes. Note that this operation can take several hours to complete depending on the size of the disk and the speed of the rebuild operation. The speed of the rebuild operation can be adjusted with the DELAY and EXTENT parameters of the TIER command. In addition, the rebuild operation can be stopped, or paused and resumed with the TIER STOP, TIER PAUSE, and TIER RESUME commands. The TIER AUTOREBUILD command can be used to automate the rebuild process. Note that SPARE disks are handled slightly differently from other disks, in that SPARES that are not in use as an active replacement for a failed disk elsewhere in the system are simply returned to a normal healthy status by this command; SPAREs that are in use are already considered healthy and are not rebuilt. The failed disk to be rebuilt is specified by its physical tier and channel locations, ‘tc’, where:

‘t’ indicates the tier in the range <1..128>, and
‘c’ indicates the channel in the range <ABCDEFGHPS>.

All failed and replaced disks can be rebuilt using the ALL parameter.

REBUILDVERIFY=ON|OFF

This parameter determines if the system will send SCSI Write with Verify commands to the disks when rebuilding failed disks. This feature is used to guarantee that the data on the disks is rebuilt correctly. Note: This feature will increase the time it takes for rebuilds to finish.

Default is OFF.

REPLACE[=tc]

This parameter tells the system to replace the specified failed disk with a spare disk or replace a healthy disk that is believed to be on the verge of failing. The healthy disk replacement is referred to in the system as a proactive replacement operation. A replace operation is used to temporarily replace a disk with a healthy spare disk. This operation can take several hours to complete depending on the size of the disk and speed of the replace operation. The speed of the replace operation can be adjusted with the DELAY and EXTENT parameters of the TIER command. The disk to be replaced is specified by its physical tier and channel locations, ‘tc’, where:

‘t’ indicates the tier in the range <1..128>, and
‘c’ indicates the channel in the range <ABCDEFGHP>.

(Note that spare disks themselves cannot be replaced with this command).

RESTART[=tc]

This parameter tells the system to start a restart operation on a (presumably) already failed disk.The failed disk to be restarted is specified by its physical tier and channel locations, ‘tc’, where:

‘t’ indicates the tier in the range <1..128>, and
‘c’ indicates the channel in the range <ABCDEFGHPS>.

All failed and replaced disks can be restart using the ALL parameter.

SCAN

This parameter checks each disk channel in the system for any new disks and verifies that the existing disks are in the correct location. It also starts a rebuild operation on any failed disks which pass the disk diagnostics.

STATUS

Displays the loop status of each disk channel and a count of the fibre channel errors encountered on each channel.

STATUSCLEAR

Resets the fibre channel error counts on each disk channel.

TIMEOUT=x

This parameter sets the total disk timeout (in seconds) for an I/O request. The total disk timeout value indicates the total overall length of time allotted to each I/O request to complete; if an I/O request has not completed within this time frame, then an error status is reported for it. This parameter must be greater than or equal to CMD_TIMEOUT. Valid range is 1 to 512 seconds.

Recommended value for SAS drives is 27 seconds.
Recommended value for SATA drives is 60 seconds.

Default is 60 seconds.

WRITESAME=ON|OFF

Enable and disables use of the SCSI Write Same command when formatting LUNs. The SCSI Write Same command is used by the system to format a LUNs faster. This parameter is provided for backwards compatibility with disks or enclosures that do not support the SCSI Write Command.

Default is OFF.