Not sure how easy this is to do on an MD600 but on my set up at home I have a QNAP TS-251 which is my primary NAS and a QNAP TS-112P that I picked up for £40 second hand on eBay (excluding any hard drive).

It’s is only a single drive and doesn’t have an Intel processor (so no good for Sooloos) but I’ve schedule a QNAP to QNAP back up every night to back up the data on the 251. Easy enough to set up and it acts as an automated backup for not too much money. The initial sync took a long time but now it doesn’t take too long each night for any additional data.

#1 G91A, DSP5000 (96/24), MS600, QNAP TS-251
596
M100 - restoration in process.