I was wondering how one can add a drive into an existing RAID array while ESXi is still running. I have read that you are able to use Dell OpenManage to do this. I have installed OMSA 7.0 on the VMWare ESXi host (5.0 and fully updated) and I've installed OpenManage Essentials on a Windows Server 2008 R2 guest. The issue that I'm having is that OpenManage is unable to see my RAID controller. I have seen videos and photos as parts of guides on how to do this online, so I would assume that the functionality exists and I just have it set up wrong.
It would be helpful to know the RAID controller, but I think this may be a limitation of OME+ESXi as discussed here. It's possible you can manage the storage via OMSA Managed Node (as opposed to OME) from the Windows box.