Hi, my DIY NAS has ran out of SATA ports and I was considering to add an external 2-bay USB enclosure for which I’d need the disks to be in RAID 1.

These are the options I came across:

  • Buying an enclosure with a RAID controller within itself: on paper sounds good but people complain that these controllers are often unreliable, use proprietary file systems and hide away some functionalities such as the scrubbing
  • Buying an enclosure without any RAID controllers, just passing JBOD to the Operating System and RAID-ing from there. People discourage this approach because they say that the USB cable, being not latched, risks sudden disconnections. I came across this nice blog post written by a TrueNas maintainer listing other problems but to me it seems that as long as I buy the DAS from a reliable brand (so no bugs in the chipset hopefully) and I make sure not to disconnect the USB cable, everything should work well, shouldn’t it? Are there other reasons for which a connection over USB should be less reliable than a connection over SATA?

Thank you for your time.