Welcome @Bowlsys to the Rockstor community forums. Quick question, do you want to keep the external USB drives, or are you asking about moving the data from the USB drives to the Rockstor array? If it is the latter, then you can look at some other forum entries like here:
If it is the former, then by mounting the external drives (especially if they’re formatted in ext4 or something) you will have access to them, however that would probably defeat the purpose of moving to a system designed using the btrfs filesystem).
If you want to do more searches, you can do that from the top of the site page. In case you can’t see the search symbol (a little faint, and @phillxnet will eventually get to it with everything else on his plate), it’s located here:
