Are USB external multiple disk cases reliable enough for RAID?

Question

Next summer I'll be building a new bigger home file server and repurpose my current one as daily|weekly automated backup (wake up, sync, sleep) for most important data. The one I'm using now (1) worked flawlessly for like 7 years with the only downtime due to disk upgrades and I would like to maintain a similar configuration on the new one as well, however I wonder if a multiple USB3 disk drive dock case (2) could be a reliable solution today.I'd put there a maximum of 5 disk pairs arranged as ZFS mirrors. My current server case wouldn't allow more removable disks so I have to move to a bigger one, but SATA capable ones cost a lot more, therefore not being in need of great performance, I wonder if I could trust USB for that use. I'm not sure if XigmaNAS, which is FreeBSD based, would support that; in that eventuality I would consider moving to a Linux solution such as OpenMediaVault or similar dedicated systems. Actually there is a similar case model with one eSATA port and 8 drive bays, but I've read about potential incompatibilities with port replicators, so I'm not sure what to choose. Any ideas?1- Self built. XigmaNAS on a Supermicro X7SPA-L Atom Mini-ITX board, two ZFS pools plus one non mirrored disk for non important uses. All disks on internal SATA ports plus one on a ASM1062 PCI-E card I added.2- https://icybox.de/en/product.php?id=301

LinuxBender · Accepted Answer

Are USB external multiple disk cases reliable enough for RAID?I think they are. I've had similar setups in the past though not ZFS. I've done this with LVM. In my experience it may be a good idea to not put any part of the OS on that raid, set the mount option "noauto" and have a background script that checks the raid/volume health first and then mounts it in the event that any USB connections are loose or disconnected or late to power up. That way you can always get into the OS without anything hanging.

rektide · Answer

I've been so slow to make it happen but my ceph/rook cluster premise is that this is fine. Usb really should not be a problem at all.

compressedgas · Answer

Those poor USB to SATA interface chips though need more cooling than they are given.