vSphere Storage Appliance

I have a need to extend a disk that is currently presented as a physical mode RDM to a single VM on an ESXi host running 5.5 build 3116895.

I have followed the procedure per the article below:

Expanding the size of a Raw Device Mapping (RDM) (1007021) | VMware KB

To clarify, the process I followed was:

1.  Added the additional storage to the SAN (EMC VNX5600)

2.  Ran HBA rescan on the host.

3.  Ran Rescan in Disk Management on the Windows VM.

So here is the problem:

Neither my host nor my VM guest OS appears to recognize the additional storage.  There are no snapshots for the VM (physical mode RDM does not support snapshots).  I've followed this same process on another VM on another host in a different cluster (with the same build of ESXi) and I do not experience the same issue.  The host recognizes the new storage immediately after the rescan and it is immediately displayed as unallocated space on the VM guest after running a rescan disks from within windows disk management tool. 

Unfortunately, this is a business critical application that cannot be restarted without upsetting a lot of people and going through a difficult approval process.   According to the article I linked above, and my testing, I should not have to restart this in order to recognize the additional storage on the LUN.

I was curious if anyone else had run into this in the past and if so, what action needed to be taken to resolve the problem?

Can you confirm if that volume is replicated by RecoverPoint? If yes, check the following: http://www.mikes.eu/index.php/how-to/254-how-to-resize-a-lun-that-is-already-replicated-by-emc-recoverpoint.html

The LUN is replicated by recoverpoint.   Thanks for the suggestion.  I'll give this a try and let you know how it turns out!

It was in fact a RecoverPoint issue.  There was an option in recovery point to resize the replication set.  After selecting that option, the host was able to see the additional storage.  Then we were able to add it to the Virtual Machine.