Missing LUN information when GetFCPTargetMapping is called in Windows Server

Applies to: Windows Server 2008 R2 EnterpriseWindows Server 2008 R2 DatacenterWindows Server 2008 R2 Standard


When you use a third-party application or the Fibre Channel Information tool (fcinfo) to call the GetFCPTargetMapping function in Windows 2008 R2 through Windows Server 2016, some target and logical unit number (LUN) information is missing.

This issue occurs if the following items are in the same zone:

  • Multiple Fibre channel controllers
  • Installed Microsoft Multipath I/O (MPIO) that has the Round Robin policy configured
  • The installed Microsoft device-specific module (DSM)

When you run the fcinfo.exe /mapping /ai:0: cmdlet in an environment that has two LUNs, the following results can occur:

Incorrect result (a device is missing) Correct result
(DeviceName, B, T, L)
( \\.\PhysicalDrive1, 0, 0, 0)

(DeviceName, B, T, L)
( \\.\PhysicalDrive1, 0, 0, 0)
( \\.\PhysicalDrive2, 0, 0, 1)

Note B = Bus, T = Target, L = LUN


The missing information causes no outages or data loss.