Multipath IO (MPIO) is required when more than one computer system is attached to the same set of shared disks. MPIO is also required when attaching additional storage externally via the SAS ports located on the rear of each of the system nodes or using iSCSI.
When displaying the physical disks attached to a computer with shared disks, and the shared disks are connected by multiple paths (for example redundant SAS cables), then the same disks will be displayed multiple times (once for each physical data path). MPIO is a software feature which resolves the disk data paths and presents a single path to the system. When doing the command
GET-PHYSICALDISKS and MPIO is installed and functioning, then the physical disks should be displayed correctly regardless of the number of data paths.
Open a PowerShell windows as administrator and run the following commands
Enable-WindowsOptionalFeature –Online –FeatureName MultiPathIO
Enable-MSDSMAutomaticClaim –BusType SAS
Update-StorageProviderCache –DiscoveryLevel Full
# ***The system will then likely require a reboot***