On 02.04.2020 06:07, Martin McCormick wrote: > I have killed an 8 GB thumb drive while doing an experiment. > > I had 2 8 GB PNY drives. One has a FAT 32 file system > and the other had no partitions on it as I had deleted the ones > that were there. > > The good drive had it's UUID tagged to mount on a > directory I called /flash. The fstab entry is > > UUID="3453-A839" /flash vfat rw,user,noauto 0 0 > #UUID="5A0D-76AA" /flash vfat rw,user,noauto 0 0 > > I decided to make a full copy of the good drive to an > identical PNY 8 GB drive which was the one with all the > partitions deleted. > > The good drive was /dev/sde and the soon to be murdered > drive was /dev/sdd so my copy command was: > > dd if=/dev/sde of=/dev/sdd > > It worked and I now had two drives with the same UUID. > > I mounted the doomed drive as /flash and did a rm -r > /flash/* so now I had an empty drive whose UUID is the same as > the good drive. > > Out of curiosity, I wondered what might happen if I had > two thumb drives containing the same UUID. > > After plugging both in to a usb extender, the good drive > is still good. That's the one whose files I did not delete. > > The drive I killed now does not register anything at all. > It's as if nothing had been plugged in to any USB port. I > plugged it in to another debian system that didn't witness any of > what I had just done and absolutely nothing happened there > either. > > There is no data emergency here, but what on Earth did I > do to the empty drive to make it not even show an error in > syslog? > > I am sure that having two devices with the same UUID is > not good, but I expected some sort of error message, not a total > destruction of one of the two drives. > > The now dead drive was behaving normally until I plugged > them both in at once. > > I was going to do a mount /flash and see what the system > did but it appears that just having both drives plugged in was > sufficient to draw some blood, so to speak, somewhere. > > The good drive contains some ebooks and I was planning > to put different ebooks on the dead drive but that is not going > to happen unless I can make the dead drive show up again. > > Are there any open-source rescue programs in Linux that > one can run to mess with the on-board controller of the thumb > drive? This obviously killed the target drive since it was > working right up to when it stopped working. > > Thanks. > > Martin McCormick > WB5AGZ > I think thumb drive failed because of physical damage and by pure coincidence. That is, if you watch syslog [1] when plugging in faulty usb thumb drive and there is no messages about inserted hardware. I'd check for those in the first place. >From low-level perspective any plugged in usb device is different, at least because of different port IDs, so operating system would tell them apart even if data\filesystems on them are identical. I suspect physical damage was done to lines or solder joints of usb connector or controller IC by bent PCB, or a static discharge fried a controller IC.
[1] # tail -f /var/log/syslog -- With kindest regards, Alexander. ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system ⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org ⠈⠳⣄⠀⠀⠀⠀
