Hello!
Since upgrading to 1.5.3, my USB backup drive has started unmounting. I’ve verified via terminal that the disk remains connected but is no longer mounted. I already set ‘Disk Standby’ to ‘Never,’ but the issue persists. Since this is my primary backup drive, I need it to stay mounted at all times.
Any ideas on what might be causing this?
UUID=1234-ABCD /media/backup ext4 defaults 0 2
Explanation of the fields:
UUID=1234-ABCD → The unique identifier of the disk/partition (you can find it with blkid).
/media/backup → The mount point, i.e. the folder where the drive will be attached.
ext4 → The filesystem type (e.g. ext4, btrfs, ntfs, xfs). defaults → Standard mount options (can be customized, e.g. noatime, rw`).
0 → Dump option (usually 0).
2 → fsck order during boot (root filesystem = 1, others = 2).
Important: Create the mount directory (/media/backup) beforehand and make sure the UUID is correct. Once added to /etc/fstab, the drive will be mounted automatically at startup.
Hello, sny.
I’ve already edited the fstab file with the disk’s UUID, but it keeps unmounting after a while.
I’ve connected the disk to another USB port, and it hasn’t unmounted at least for now.
This might seem out of left field and I’m probably asking something irrelevant to your issue, but how is your USB drive listed when you run lsblk?
sdd
└─sdd1
OR
sdd
└─sdd
with or without the 1 after s** ?
sdd1 and sdd2 as I have to partitions
From what you’ve described, this isn’t an fstab issue at all. The disk isn’t “forgetting” its UUID, the kernel is actually dropping the mount because the USB device briefly resets. When that happens, fstab can’t remount it, because as far as the system is concerned the drive momentarily disappeared.
This lines up with what changed in 1.5.3. USB power management is more aggressive, and some drives now get pushed into suspend or momentary resets. That’s why switching to another USB port suddenly makes it stable, different ports behave differently under load.
To confirm it, the next time the drive unmounts, run:
dmesg | tail -n 30
If you see messages about “USB reset”, “I/O errors”, or “filesystem shut down”, then this is exactly the issue.
You can also test with USB autosuspend disabled (not permanent, just diagnostic):
echo -1 > /sys/module/usbcore/parameters/autosuspend
If the drive stops dropping after that, then we know it’s a 1.5.3 power-management regression rather than anything wrong with your configuration.
Let us know what dmesg shows and we can pinpoint the exact cause quickly.
Before changing the port, I disabled USB autosuspend, and the issue remained. Since I connected to the other port, I haven’t had a single drop.
Thanks for confirming that.
That actually tells us something important.
If disabling autosuspend didn’t help, but moving the drive to a different port completely stopped the disconnects, then the root cause isn’t power-saving. It’s the USB controller path on that specific port.
Different USB ports often sit behind different hubs or internal controllers, and some ports on certain boards are more sensitive to momentary voltage dips or link resets. When 1.5.3 tightened its USB handling, that sensitivity showed up as random unmounts on the original port.
By moving the drive to a more stable controller path, you’ve effectively sidestepped the issue — which is why it hasn’t dropped once since.
If the drive stays stable on the new port, you can safely leave it there. If it happens again, run:
dmesg | tail -n 30
and we can pinpoint the exact cause.