If you are in need of increasing space on any drive (mainly in regards to servers), I highly recommend this tool: AOMEI Partition Assistant (PA) A great tool that is easy to use and works!
Just a few notes:
- MAKE A BACKUP OF ALL DRIVES BEFORE STARTING! - DO THIS, don't be lazy and regret it later.
- If you are going to use it on a server, buy the PA Server edition.
- The partition you are wanting to increase MUST be on the same array (and disks) that has available space (or if you are shrinking a drive to make room - still has to be on the same array).
- You must shrink at the beginning of the drive to add to another partition... remember RAID is linner in design.
- Be patient! It can take up to 4-10hrs depending on how much data has to be moved/shrinked. Once the server restarts you'll see progress, it may hang... that is okay just wait, observe the hard drive lights for activity. One of the times I did it, it "hung" up at 38% and stayed there, I just waited overnight and then in the morning (there was no HD activity thus...) did a hard reset and all was good. Again; BE PATIENT and WAIT... give it time.
https://www.disk-partition.com/compare-edition.html
Enjoy.