HP RAID array - hpacucli

In order to just add the disk and make a 4-disk RAID5 array, you'll need to run:

ctrl slot=0 ld 1 add drives=1I:1:4

That will add the disk, redistribute data across the array and expand the logical drive. Here's a cheat-sheet.

You do have other options, like adding the drive to the array and carving out a new logical drive of the unused space, or with an entirely different RAID level. These are very flexible controllers.

Either way, the line above will accomplish what you want.

As for the RAID5 objection, here's an explanation. These are enterprise SAS disks, so you'll be okay... but in general, people are moving away from RAID5 as a recommended drive RAID level as disk sizes increase.