Installed Archlinux on a USB pen-drive (ext4) about a month ago.

Everything was working fine up until recently. After a while I would not be able to execute commands (except bash built-ins).
$ ls
-bash: /usr/bin/ls: Input/output error
$ ls
-bash: ls: command not found
$ bash
Bus error

When this happens a reboot usually "fixes" the problem temporarily. Everything would be working again but these errors would come up eventually again. When they do the system becomes unusable and I have to reboot again. This makes it difficult to troubleshoot the issue.


  • First backing up all important data
  • Booting into a "live usb" and doing fsck on the partition in question
  • Freeing up some disk space on the partition in question
  • Plugging in the USB pen-drive to a different USB port and making sure it's plugged in correctly
  • Staying logged in as root to try to peek echo "$(</proc/kmsg)" - doesn't work
  • Running dmesg -n err did produce errors in the VT console eventually but forgot to write them down. Will add them to this post if I see them again and if relevant. I remember it mentioning the journal.


I remember having similar problems years back when installing Linux on a USB drive. I remember it having something to do with disk caching and the lifespan of the device. Of course this may be about something different.

I was considering doing `dd if=/dev/sdd of=/dev/null` to see if I get any errors. Haven't done that yet but will and will post results - if you think it's relevant.

What I'd like ideally is to:
  • Find out what exactly the problem is
  • See if I can still save this storage medium
  • Prevent this from happening again in the future with another USB drive.
  • Check if there's anything I could do to not have to reboot

Let me know if there's anything else I should try and what the most likely explanation could be for what is happening.

Don't know how relevant this is but I noticed with iostat that something is constantly trying to write to the drive every few seconds. Looking into this currently. Apparently it's to do with /sys/module/workqueue/parameters/power_efficient

6114 be/4 root        0.00 B/s    0.00 B/s  0.00 % 69.00 % [kworker/u8:6+events_freezable_power_]
7945 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.11 % [kworker/u8:5-events_freezable_power_]
7207 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.01 % [kworker/u8:1-events_freezable_power_]
  • I think you're on the right path. I think you should try the dd command. You may also be able to get the USB drive to execute a self-test using smartctl: smartmontools.org – Emmanuel Rosa Jul 5 at 12:41
  • Check dmesg output when errors start coming. Most USB pen drives are incompatible with smartctl. – Artem S. Tashkinov Jul 5 at 12:57

Input/output errors are always hardware. You may try different USB ports but I assume the stick to be the problem. Maybe after some time when it has got warm.

I suggest to throw away the stick.

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