Can I expand storage without replacing existing drives?

I have an EX2 Ultra with 2 6TB drives in RAID1 mode. It’s used primarily for media storage streamed using a Plex server on an NVidia Shield TV Pro. I’m wondering if there is a way to keep the 2 6TB drives in the EX2 Ultra, and add additional drives that the EX2 Ultra would manage just like it does the 2 internal 6TB drives, without changing them in any way.

I’ve read what is in the help about things like iSCSI that sound like possibilities, but I just don’t have enough experience with these things, or NAS in general, to know if any of them will do what I want. Or if what I want is even possible. I’d just prefer to not have to “throw away” the 2 6TB drives I currently have by replacing them with larger drives if I can just add additional drives to the configuration. Thanks in advance.

You can Expand the storage using External USB hard drives … but they will be separate from RAID1 mode and be treated as Network drives.

When you attach a USB drive to the WD My Cloud EX2 device, you turn it into a network drive. Once connected, the USB drive has the following capabilities:

  • When you connect an external USB drive such as a WD Passport, a memory stick,or a camera to the WD My Cloud EX2 device, you can access it with WindowsExplorer or Mac Finder.
  • The USB drive can serve as a target for backups.
  • You now have the option of mapping the drive as a user share drive.

http://products.wdc.com/library/UM/ENG/4779-705119.pdf