Rescuing a Flaky JMicron USB Backup Drive That Kept Going Read-Only
June 20, 2026 19:00
My external USB backup drive started misbehaving: it took ages to mount, sometimes did not mount at all, and when it did mount it would flip itself to read-only within seconds. It turned out to be two problems feeding each other – a buggy USB-to-SATA bridge and a corrupted ext4 filesystem – and crucially they had to be fixed in the right order, or the repair simply would not stick.

















