LUN¶

LUN Displays the status of, or Adds/Removes LUNs. This command is used to change the configuration settings for the LUNs in the system and to monitor their status. This command allows the user to create LUNs with the ADD parameter and delete LUNs with the DEL parameter. The FORMAT parameter can be used to format LUNs after they are created. A LUN must be formatted before it can be used. The ADD parameter will prompt the user to format a LUN after it has been added to the system. The speed of the LUN format operations can be adjusted with the DELAY and EXTENT parameters of the TIER command.

ADD[=x]

This parameter will add a 64-bit LUN to the system. The system will prompt the user for all the necessary information to create the LUN and will indicate if the LUN was successfully added to the system. The system can support up to 1024 LUNs. The LUN to be added can be specified by ‘x’, where ‘x’ is in the range 0..1023.

ADD32[=x]

This parameter will add a 32-bit LUN to the system. The system will prompt the user for all the necessary information to create the LUN and will indicate if the LUN was successfully added to the system. The system can support up to 1024 LUNs. The maximum capacity of a 32-bit LUN is limited to 0xFFFF0000 host blocks.

Block size	Maximum Capacity
512	2.097.120 MiB
1024	4.194.240 MiB
2048	8.388.480 MiB
4096	16.776.960 MiB

The LUN to be added can be specified by ‘x’, where ‘x’ is in the range 0..1023.

ADD64[=x]

This parameter will add a 64-bit LUN to the system. The system will prompt the user for all the necessary information to create the LUN and will indicate if the LUN was successfully added to the system. The system can support up to 1024 LUNs.

The LUN to be added can be specified by ‘x’, where ‘x’ is in the range 0..1023.

APTPL

This parameter allows the user to enable SCSI 3 persistant reservations support for AIX Host on a specific LUN

APTPL=ALL

This parameter allows the user to enable SCSI 3 persistant reservations support for AIX Host on all valid LUNs

CONFIG

Display the configuration information about all the valid LUNs in the system.

DELAY=x

This parameter sets the system verify delay value to ‘x’. The verify delay value determines how long a verify operation will pause after it reaches the verify extent. This parameter slows down the verify operation so that it will not affect the performance of the system. This value is in 100 millisecond increments. The range for ‘x’ is 0 to 1000.

DEL|DELETE[=x]

This parameter will delete a LUN, ‘x’, from the system. It will delete all of the data in the LUN. The LUN to be deleted can be specified by ‘x’, where ‘x’ is in the range 0..1023.

EXTENT=x

This parameter sets the system verify extent value, ‘x’, in MiB. The verify extent determines how much data can be verified before the verify operation must pause. This parameter slows down the verify operation so that it will not affect the performance of the system. Increasing the extent value will allow more data to be verified in a single pass. The range for ‘x’ is 1 to 128 MiB.

FORMAT[=x]

This parameter will perform a destructive initialization of a LUN by over-writing all the data on the LUN with zeroes. The LUN to be formatted can be specified by ‘x’, where ‘x’ is in the range 0..1023.

LABEL[=x]

This parameter allows the user to change the label of the LUN. A LUN label can be up to 16 characters long. The LUN to be labeled can be specified by ‘x’, where ‘x’ is in the range 0..1023.

LIST

Display a list of all valid LUNs in the system. The list shows the capacity, owner, status and serial number of each LUN.

The following is a list of possible statuses and their definitions:

‘Not Installed’ - The LUN does not exist.
‘Config Error’ - The LUN has a configuration error.
‘Unavailable’ - Cache data for the LUN is being purged. This is done when the LUN is being deleted or mirrored by the other unit in the system.
‘Not Ready’ - The unit is still booting up.
‘Stopped’ - The unit was stopped.
‘Unformatted’ - The LUN has not been formatted.
‘Critical’ - The LUN has a failed disk.
‘Critical [GHS]’ - The LUN has a failed disk and a disk that is replaced by a spare.
‘Degraded’ - The LUN has a failed disk (8+2 Only).
‘Degraded [GHS]’ - The LUN has a failed disk and a disk that is replaced by a spare (8+2 Only).
‘Ready [GHS]’ - The LUN has a replaced disk.
‘Ready’ - The LUN is OK.

[LOCK[=x]]

This parameter will lock a LUN in the data cache. It will keep all of the data for the LUN in the cache for faster access. Up to 50 percent of the data cache can be used for locking LUNs. The LUN to be locked can be specified by ‘x’, where ‘x’ is in the range 0..1023.

LOCKOUT_CLEAR=type

This parameter is is used to clear a lockout code on the prompted LUN so that admin can clear an event from a particular lun. Clearing this field will remove the lockout state from the LUN regardless of the enabled setting at the system level.

‘ALL’ - Disables system from locking out LUNs from all reasons below
‘BBM’ - Disables system from lockint out LUNs when BBM is enabled and crosses a shutdown threshold or becomes full.
‘UNIT_PROBLEM - Disables system from locking out LUNs when it is determined that the problem could cause potential data loss.

LOCKOUT_DISABLE=type

This parameter specifies whether or not the system can determine when a LUN should NOT be locked out from new host accesses. Regardless of what state the system determines, we cannot lockout host access at run time due to the lockout type.

‘ALL’ - Disables system from locking out LUNs from all reasons below
‘BBM’ - Disables system from locking out LUNs when BBM is enabled and crosses a shutdown threshold or becomes full.
‘UNIT_PROBLEM - Disables system from locking out LUNs when it is determined that the problem could cause potential data loss.

LOCKOUT_ENABLE=type

This parameter specifies whether or not the system can determine when a LUN should be locked out from new host accesses. Examples of when a LUN will be locked out internally would be when the BBM is enabled and becomes full. Another example would be when a multi-channel failure exists on the LUN. The default setting of the parameter is 0, indicating no internal reasons can cause a lun to be locked out from a host.

‘ALL’ - Allows system to restrict LUNs from all reasons below
‘BBM’ - Allows system to restrict LUNs when BBM is enabled and crosses a shutdown threshold or becomes full.
‘UNIT_PROBLEM - Allows system to restrict LUNs when it is determined that the problem could cause potential data loss.

MOVE[=x]

This parameter will change the ownership of a LUN from one unit to the other when the units are in dual mode. This command will override all the configuration checks and allow the user to move any LUN. The system will display a list of all the tiers and other LUNs that need to be moved in order to move the LUN specified. The LUNs should not be moved while any unit in the system has active format, verify, rebuild or mirror operations. The LUN to be moved can be specified by ‘x’, where ‘x’ is in the range 0..1023.

PAUSE[=x]

This parameter will pause all active LUN maintenance operations including format, verify and mirror operations. A single LUN can be specified ‘x’, where ‘x’ is in the range 0..1023.

RELEASE[=x][=ALL]

This parameter allows the user to release all SCSI reservations and registrations on the LUN. The command LUN RESERVATIONS can be used to view the current SCSI reservations and registrations on the LUNs. All LUNs can be specified by RELEASE=ALL or a singe LUN can be specified by ‘x’, where ‘x’ is in the range 0..1023.

RESERVATIONS[=x]

This command displays the current SCSI reservations and registrations on the LUNs in the system. The system supports the following types of SCSI reservations:

SPC-2 - Compatible with SPC-2
Wr_Ex - Write Exclusive
Excl - Exclusive access
Wr_RO - Write exclusive registrants only
Ex_RO - Exclusive access registrants only
REG - Indicates a SCSI registration on the LUN.

The ‘Port’ column indicates the unit and host port the reservation or registration was made on. A specific LUN can be viewed by ‘x’, where ‘x’ is in the range 0..1023.

RESUME[=x]

This parameter will release all the paused LUN maintenance operations including format, verify and mirror operations. A single LUN can be specified ‘x’, where ‘x’ is in the range 0..1023.

START

This parameter allows the user to start all the LUNs that have been stopped by a SCSI START/STOP request. This parameter is not related to the STOP parameter.

STOP[=x]

This parameter will abort all active LUN maintenance operations including format, verify and mirror operations. A single LUN can be specified ‘x’, where ‘x’ is in the range 0..1023. Note that it does not, however, change the Background Verify setting for the affected LUN(s). Use ‘LUN VERIFY=OFF’ to change the Background Verify setting for a LUN.

UNASSIGN_LIST

This parameter allows the user to view the system LUNs that have not been assigned to a user or port.

UNLOCK[=x]

This parameter will unlock a LUN and release the cache locked by the LUN. The LUN to be unlocked can be specified by ‘x’, where ‘x’ is in the range 0..1023.

VERIFY

Displays the current background verify settings for all LUNs in the system.

VERIFY=ON|OFF

Prompts the user for a list of LUNs on which background verify will be turned either ON or OFF. The ‘VERIFY=ON’ argument will turn on background verify for the specified LUN(s), optionally running in continuous mode. A ‘VERIFY=OFF’ command, however, only turns off the Background Verify setting for the specified LUN(s). Therefore, any verifies already active on the LUN(s) will not terminate until after the completion of that verify’s current iteration. To stop all Verify operations immediately, use ‘LUN STOP’.

VERIFY=x

Turns ON background verify for LUN ‘x’, where ‘x’ is in the range 0..1023.

VERIFYCLEAR[=x|ALL]

This parameter allows the user to clear the verify count and the time of last verify for a specific LUN designated by ‘x’ or all LUNs.