Hi, Are you wanting to add the new drives to the existing RAID 5 or create a new RAID 5? If you are creating a new one, doing it in the controller should not be any problem. If you are wanting to expand the existing array that has to be done in OMSA and not in the controller. You can use OMSA for ESXi [URL]  
Greetings all, I need to expand the storage on a server running non-critical VMs. I currently have 3 x 600GB drives and one VD in raid 5. We will be adding 3 more identical drives, staying in raid 5 to increase storage.  I've read a couple of posts regarding similar upgrades where the user was instructed to use OMSA in order to add the drives and preserve data. This server isn't running Windows, it's running VMESXi 5.5.0.  I will be adding the drives directly through the PERC controller.... Is my data in danger doing this? Should I count on adding time for re-installing VMESXi and restoring my VMs?  Thanks in advance!  J
Adding 3 drives to PERC H700 in PowerEdge R710