I am adding two 600 GB disks to an HP P2000 array that is connected to an HP DL380 G6 which is running the free version of esxi 4.1.0. The esx server hosts a number of development VMs. Two of the existing datastores are RAID 5 volumes from the P2000. The other datastore is a RAID 1 volume consisting of the DL380 internal disks. Once I have added the disks to one of the RAID 5 volumes and increased the size of the volume on the P2000 can I safely increase the size of the corresponding datastore within vSphere? I see an "increase" option under the datastore properties.
if the ESXi host can see the additional space on the LUN, then you can grow the datastore online. If it is not seen yet, perform a rescan on the HBA first.
A backup is always good to have. However, volume growth can usually be done without interruption (I've done it a couple of times). Only make sure the new LUN size does not exceed the maximum allowed size of 2TB minus 512 Bytes. This would make the LUN unusable for ESXi!
