In ESXi, the MPIO driver sets the default "Active/Optimized" to storage controller 1 and "Standy" to storage controller 2 when ALUA/LunAffinity are enabled on the controllers.

The above settings can easily be changed so that the "Active/Optimized" is default to storage controller 2 and "Standby" default to storage controller 1 for any individual LUN. The objective is to balance the access to the LUNs across both controllers for better performance.

For example, in a case where the "Active/Optimized" is set to storage controller 2, and "Standby" is set to storage controller 1 for LUN A, only I/Os accessing LUN A are passing through storage controller 2. Vise versa is also true for say LUN B..

Steps to assign "Active/Optimized" and "Standby" for any LUN.

NOTE: You need to know the respective WWPN of the host HBA ports and Storage WWNN.. These can be looked up through Promise CLI or Promise WebPam GUI.

  1. Open vCenter Sever and select the appropriate HBA as indicated below:



  2. Select a LUN as indicated above by right click on it and select "Manage Paths" as indicated below. 




  3. Then select which prefered path the to set this LUN to (storage controller 1 or storage controller 2)  Note:  Make sure that the LUN policy is set to "Fixed (VMware)" as indicated below.



CLI output of Logdrv -v before making changes: 


-------------------------------------------------------------------------------

LdId: 66

ArrayId: 4                             SYNCed: Yes

OperationalStatus: OK

Alias:

SerialNo: 495345200000000000000000E2BE857E74045600

WWN: 22b3-0001-55f2-763b               PreferredCtrlId: 1

RAIDLevel: RAID0                       StripeSize: 64 KB

Capacity: 249.49 GB                    PhysicalCapacity: 249.49 GB

ReadPolicy: ReadAhead                  WritePolicy: WriteBack

CurrentWritePolicy: WriteThru

NumOfUsedPD: 1                         NumOfAxles: 1

SectorSize: 512 Bytes                  RAID5&6Algorithm: N/A

TolerableNumOfDeadDrivesPerAxle: 0     ParityPace: N/A

Raid6Scheme: N/A

HostAccessibility: Normal

ALUAAccessStateForCtrl1: Active/optimized

ALUAAccessStateForCtrl2: Standby

AssociationState: no association on this logical drive

StorageServiceStatus: no storage service running


-------------------------------------------------------------------------------

LdId: 67

ArrayId: 4                             SYNCed: Yes

OperationalStatus: OK

Alias:

SerialNo: 4953452000000000000000000A987EF44E93A434

WWN: 2284-0001-55f3-b451               PreferredCtrlId: 2

RAIDLevel: RAID0                       StripeSize: 64 KB

Capacity: 249.49 GB                    PhysicalCapacity: 249.49 GB

ReadPolicy: ReadAhead                  WritePolicy: WriteBack

CurrentWritePolicy: WriteThru

NumOfUsedPD: 1                         NumOfAxles: 1

SectorSize: 512 Bytes                  RAID5&6Algorithm: N/A

TolerableNumOfDeadDrivesPerAxle: 0     ParityPace: N/A

Raid6Scheme: N/A

HostAccessibility: Normal

ALUAAccessStateForCtrl1: Active/optimized

ALUAAccessStateForCtrl2: Standby

AssociationState: no association on this logical drive

StorageServiceStatus: no storage service running


CLI output of Logdrv -v after balancing the LUNs:


-----------------------------------------------------------------------------

LdId: 66

ArrayId: 4                             SYNCed: Yes

OperationalStatus: OK

Alias:

SerialNo: 495345200000000000000000E2BE857E74045600

WWN: 22b3-0001-55f2-763b               PreferredCtrlId: 1

RAIDLevel: RAID0                       StripeSize: 64 KB

Capacity: 249.49 GB                    PhysicalCapacity: 249.49 GB

ReadPolicy: ReadAhead                  WritePolicy: WriteBack

CurrentWritePolicy: WriteThru

NumOfUsedPD: 1                         NumOfAxles: 1

SectorSize: 512 Bytes                  RAID5&6Algorithm: N/A

TolerableNumOfDeadDrivesPerAxle: 0     ParityPace: N/A

Raid6Scheme: N/A

HostAccessibility: Normal

ALUAAccessStateForCtrl1: Standby

ALUAAccessStateForCtrl2: Active/optimized

AssociationState: no association on this logical drive

StorageServiceStatus: no storage service running


-------------------------------------------------------------------------------

LdId: 67

ArrayId: 4                             SYNCed: Yes

OperationalStatus: OK

Alias:

SerialNo: 4953452000000000000000000A987EF44E93A434

WWN: 2284-0001-55f3-b451               PreferredCtrlId: 2

RAIDLevel: RAID0                       StripeSize: 64 KB

Capacity: 249.49 GB                    PhysicalCapacity: 249.49 GB

ReadPolicy: ReadAhead                  WritePolicy: WriteBack

CurrentWritePolicy: WriteThru

NumOfUsedPD: 1                         NumOfAxles: 1

SectorSize: 512 Bytes                  RAID5&6Algorithm: N/A

TolerableNumOfDeadDrivesPerAxle: 0     ParityPace: N/A

Raid6Scheme: N/A

HostAccessibility: Normal

ALUAAccessStateForCtrl1: Active/optimized

ALUAAccessStateForCtrl2: Standby

AssociationState: no association on this logical drive

StorageServiceStatus: no storage service running


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