Thank You MJ, for the clarifications.
For #2, in other words, I just need a PC with say 3GB internal HD (or 3G external HD), I don't event need separate NAS to store my music files?
For #3.. I am not sure if I understand the procedure clearly.
1. I perform normal Sooloos backup using the core in the MD600 to any external storage (e.g. external HD),
2. plug this external HD with backed up music files (I assume the file would be not in playable format) to the PC where Roon is installed
3. Run Roon, and "import" these backup file (to internal HD, or another external HD). Is Roon going to convert this back up file to playable format?
or
1. While MD600 is in the same network with Roon installed PC, I tell Roon to locate the music files in the MD600
2. Command Roon to import the music files in the MD600 to whichever format that Roon can play, to any designated location (e.g. D:\ in internal HD)
The plan here is to remove my MD600 from my system, but securing the files.
Thank You!