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USB is unreliable. I used btrfs raid0 on USB drives for more than a year. Every month or so, a drive would disconnect from the bus and immediately redetected a
by M95D 12d ago
USB is unreliable.
I used btrfs raid0 on USB drives for more than a year. Every month or so, a drive would disconnect from the bus and immediately redetected as another device (sde->sdf). Btrfs does not auto-recover from this. The choices are 1) reboot and scrub, which recovers the missing drive without doing a full resync, but it needs a reboot (any hosted site is offline for 3 minutes) and scrub takes a long time reading in the background, or 2) run btrfs replace which doesn't need a reboot, but the full resync takes even longer than a scrub and increases wear if it's a ssd because it wipes everything and writes all data again.
- dsr_ 12d agoI agree that USB is unreliable. I will point out that if you use ZFS instead of btrfs, you can specify drives to be detected via their serial number names rather than their attachment points, so a reconnect will not require a reboot. Still, don't depend on USB for anything meant to be permanently connected.
- doubled112 12d agoUSB is unreliable but it's working for me. I've had zero disconnects in a couple of years of using a Terramaster USB-C DAS. I've heard of the problems enough I've even searched logs for it. I've wondered if my experience is different because I'm using single disks (but still ZFS) instead of any RAID. There is rarely transfer happening across all of the disks.