I have a Dell PowerEdge 2970. Currently it runs as a ESXi server with a handful of VM's on it. I have 3 300GB drives plugged in to it, and 5 open trays across the front. It is setup as a hardware Raid5 from the factory. My question is if I start running low on disc space, can I just add on by pushing another hard drive into a empty slot, or will I need to back everything up and rebuild the array? If I can't just plug in another hard drive, would it be better to add 3 more drives, and build a second Raid5 to avoid losing any data that I have
How to grow a hardware Raid 5
dellraid5vmware-esxi
Best Answer
I couldn't disagree with joeqwerty more to be honest. You don't mention which controller you have but all of the PERC 5 and 6 cards can perform live array expansion, although I'd be strongly tempted to fully backup your volume first. This way your new drive/s will become part of the R5 array and so will be able to survive a single disk failure. If you simply add another extent then in the event of losing a disk you stand a good chance of losing the whole VMFS datastore (the risk lessening if you're on ESX/i v4), plus expanding the array to 6 drives gives you 300GB more space than two 3 drive arrays.