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