LUN IDs are different than original LUN IDs and multiple paths to the same LUN have different LUN IDs

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When VirtuCache is installed, the LUN (device in VMware) IDs or LUN numbers that you see in VMware are different from the LUN IDs assigned by the storage appliance to that same LUN. This is not a problem.

VMware shows different LUN IDs than the Storage Appliance ID when VirtuCache is installed
Figure Caption: VMware shows different LUN IDs than the LUN IDs assigned to this LUN by the storage appliance, when VirtuCache is installed.


Related to this is the fact that a LUN can be presented to VMware using different LUN IDs on different paths. VMware’s support might say that this is not supported by VMware, but this configuration is allowed by VMware if 3rd party software like ours uses a custom PSP to claim the LUN.¬†Below is an example of this scenario, where vmhba35 is the VirtuCache pseudo adapter and the remaining vmhbaX are physical adapters in the same host. L2 (or LUN number 2) is the LUN ID of the LUN associated with the device and L3 is the LUN ID assigned to VirtuCache pseudo adapter.¬† Both LUN IDs L2 and L3 are assigned by VirtuCache. As you can see the LUN IDs on different paths to the same device (LUN) are different. This is also not a problem if VirtuCache is installed. Also, as stated earlier, the LUN number L2 is assigned to the device by VirtuCache and it might not be the same as the LUN number originally assigned by the storage appliance to that same LUN, since LUN numbers assigned by VirtuCache have no relation to LUN numbers assigned by the storage appliance, and again this is not a problem.

vmhba3: C0: T1: L2
vmhba4: C0: T1: L2
vmhba5: C0: T1: L2
vmhba2: C0: T1: L2
vmhba35: C0: T0: L3
vmhba5: C0: T0: L2
vmhba2: C0: T0: L2
vmhba3: C0: T0: L2
vmhba4: C0: T0: L2

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