[SOLVED] Linux 4.17.8-1-ARCH #1 SMP PREEMPT: Strange USB flash drive behavior.

stf92 · 11-05-2019, 07:55 PM

Hi: I have a netbook with two USB slots. One is 3.0 and the other is 2.0. And a 3.0 USB flash drive (aka pendrive). I plug the pendrive into the 2.0 slot and run

Code:

root@darkstar~# dd if=/dev/zero of=/dev/sda bs=1M count=1000 status=progress
706740224 bytes (707 MB, 674 MiB) copied, 1 s, 707 MB/s
dd: error writing '/dev/sda': No space left on device
952+0 records in
951+0 records out
997318656 bytes (997 MB, 951 MiB) copied, 1.43623 s, 694 MB/s
root@darkstar~#

Absurd, because the pendrive (/dev/sda) is a 16GB pendrive. I unplug the pendrive and plug it into the 3.0 slot and run cfdisk. This is the output:

Code:

                  Disk: /dev/sda
                                           Size: 951.1 MiB, 997318656 bytes, 1947888 sectors
                                                  Label: dos, identifier: 0x1431def9

That is, cfdisk sees the same total size: 951MiB. And the same does parted. The pendrive is new and I have tested it on other machines. If I now turn off the netbook and turn it on again, then cfdisk reports the correct size: 14.3 GiB. Other times the above command hangs the terminal. It doesn't return the prompt and becomes irresponsive to ^C. Still other kind of behavior with the pendrive plugged in the 2.0 slot: the command in the code block (dd) gives I/O error (together with buffer I/O error). This happened up to some days ago.

However everything is normal with a 2.0 pendrive inserted in that slot (the USB 2.0 slot). What can be the cause of such a weird behavior? Is the logical conclusion that the slot is broken? I don't think so.

ondoho · 11-06-2019, 01:40 AM

Sounds like multiple problems, that could well be the result of a broken system (see here for reference).

stf92 · 11-06-2019, 06:05 PM

Thanks. I forgot to say that with the 3.0 pendrive inserted into the USB 3.0 slot I never had a problem. The problems appear when using that pendrive in the USB 2.0 slot. I also repeat that 2.0 pendrives give no problems when inserted into the 2.0 slot.

Quote:

Originally Posted by ondoho

[...] that could well be the result of a broken system.

By system you mean the software running on this machine or only the operating system? In either case that would mean the hardware is not involved, right?

EDIT: When dd notifies me the occurrence of an I/O error it is then not necessary that the hardware is failing?

masterclassic · 11-12-2019, 01:20 PM

Did you ever write the entire capacity or almost? There are fake devices that report a fake full capacity but they report errors if you try to write on them.
I had in the past a device reporting 4GB, however trying to write something more than 1GB gave error (or trying to read content above 1GB gave error, I don't remember well now). It happens sometimes with super-bargain in the "grey market".

stf92 · 11-12-2019, 06:24 PM

Quote:

Originally Posted by masterclassic

Did you ever write the entire capacity or almost?

Yes, I did, and got 'No space left on device' after writing bare 700MB in a 16GB USB pen drive.

Quote:

It happens sometimes with super-bargain in the "grey market".

Can it happen with a Kingston Technology product? It's a big firm.

Anyway I ran dd from a live Arch Linux external medium getting the same errors. So, the software in the machine, including the installed Arch Linux, is not to blame, in accordance with the notification "I/O error" as mentioned above.

stf92 · 11-17-2019, 05:16 PM

Conclusion:
(1) The suspected pen drive (aka USB flash drive) is broken.
(2) Under the following conditions: (a) No swap space. (b) 2GB RAM. (c) The Firefox DE/window manager running on top of X, dd writing an external device makes the O.S. fail.

Thanks for the feedback.