Without investing in another drive, the procedure would be to use your current snapraid parity drive as a data drive (format it with XFS in unRaid), then use the unassigned devices plugin to mount one of your current data drives, then copy the files over.
After the copy, assign the now empty drive as a data drive, format as XFS, and mount your next ext4 drive via unassigned devices
Keep repeating. You'll be left with an empty 4tb ext4 drive which you will then assign as your parity drive
Sorry for the necrobump. I successfully mounted my data drive via unassigned devices. Do you recommend a specific way of going about moving the data onto the array? I had two ways of going about it but i'm not sure which is optimal.
#1: create user shares for my media groups, then move the data folder by folder from the ext4 drive into the correct usershares
#2: move everything onto my 4tb disk share directly
what do you recommend? or is there another way? Once i move everything over i'd like to add the ext4 drive to the array as well.