New Setup Need Help


I bought a PR4100 and 3 8TB Nas hard drives and plan on buying a fourth.

I plan on using my WD for Plex Media and Photo sharing but I’d also like to use it for general purposes file storing and Time Machine backups. I pay for Google Storage and my photos are getting larger and larger and I’d like to depend less on Google’s services.

I’d like to setup my WD Raid redundancy but what happens when I add the forth drive? Do I have to back my files and resetup everything with all four drives or can I add the fourth drive to Raid or would it have to be its own backup?

Can I add the fourth drive as any size drive or it has to be 8TB

It depends on your RAID configuration. Here are some articles that may help you.

Hi jchen,

This doesn’t really answer my question, so let me rephrase it:

I’ve bought 3 8TB Nas hard drives and plan on buying a fourth one.

Main Goals to Accomplish

  • use mainly as a Plex server to stream video and photos
  • can i still use WD features if I use it mostly for PLEX


  • I want to add a 4th drive, might be 8tb might 6tb - does it have to be 8TB? What size does it have to be?
  • I know with other NAS’ you can’t add additional drives without formatting the previous drives - that’s a no can do for me.
  • I want the whole thing setup in some form of RAID configuration (leaning towards RAID 5) - just don’t know which one to be able to

a) add a fourth drive with ease (ie. no need to reformat the previous drives)
b) accomplish my goals
c) If I do RAID 5 with 3 drives can I migrate to RAID 10 without dataloss when i add the fourth drive?

I’m pretty sure you couldn’t upgrade from 3 disk raid5 to 4 disk raid10. You could achieve a very similar effect by adding the 4th disk as a hot spare to a 3 disk raid5 array.

Yes all the wd functionality is still there when running plex as an app