Checking multipathing in Windows

To check what multipathing settings a Windows server is using you can use the command line utility mpclaim.

To check the policy your volumes are currently using:

mpclaim -s -d

MPIO Disk    System Disk  LB Policy    DSM Name
 -----------------------------------------------------
 MPIO Disk1   Disk 2       RR           Microsoft DSM
 MPIO Disk0   Disk 1       RR           Microsoft DSM

The multipathing load balancing policy is shown under LB policy  so in the above case RR for Round Robin.

To view the number of paths there are to a volume enter the command  mpclaim -s -d followed by the system disk number you want more details on.  For example:

mpclaim -s -d 1

MPIO Disk1: 08 Paths, Round Robin, Symmetric Access
 Controlling DSM: Microsoft DSM
 SN: 6002AE000000013B006E3B

Supported Load Balance Policies: FOO RR RRWS LQD WP LB

Path ID          State              SCSI Address      Weight
 ----------------------------------------------------------
 0000000087060003 Active/Optimized   005|000|003|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 124

0000000087060002 Active/Optimized   005|000|002|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 122

0000000087060001 Active/Optimized   005|000|001|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 24

0000000087060000 Active/Optimized   005|000|000|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 22

0000000087060003 Active/Optimized   004|000|003|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 123

0000000087060002 Active/Optimized   004|000|002|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 121

0000000087060001 Active/Optimized   004|000|001|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 23

0000000087060000 Active/Optimized   004|000|000|001   0
 * TPG_State : Active/Optimized  , TPG_Id: 256, : 21

 

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6 thoughts on “Checking multipathing in Windows

  1. This is an insanely stupidly complicated process. This is windows – whatever happened to the “simple point-and-click solution?”

  2. Is there a way to find the disk details at once for all the drives/disks? i am having 3Par in windows 2008.

    1. From Windows 2008 you can use storage explorer and look inside storage manager. Those disk that device ID 3PARDADVV belong to 3PAR

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