Re: [tlug] Files copied to USB thumb drive completely gone

[Kalin KOZHUHAROV <me.kalin@example.com>]

On Wed, Nov 4, 2009 at 12:48, Craig Olinsky <colinsky@example.com> wrote:
> On Tue, Nov 3, 2009 at 1:05 AM, Dave M G <dave@example.com> wrote:
>>
>> Attila, Kalin, Curt,
>>
>> I was careful, as I usually am, to unmount the drive and wait for it to
>> say it's okay to remove before taking it out of the USB slot.
>
>
> I hate to add that I have also experienced "lost" files on a USB device that
> I believed to have cleanly dismounted before removing.  This hasn't happened
> frequently enough for me to spend time trouleshooting, and I've never lost
> anything permanently.
>
> This was always with a flash memory device rather than a physical drive.
>
> In all cases I've reused the same device succesfully, and thus assume the
> issue to be somewhere in the timing of the writes or dismount, rather than a
> failure of the USB device itself.

I haven't seen such issues so far, but I have noticed that some of my
(old) USB flashdrives
continue to blink for a second or two after `umount` has returned. It
seemed illogical, but
I haven't investigated it in more details (note-to-self: do it!).

Another thing in this connection, is the usual magic sequence I use to
reboot stuck kernel
Alt+SysRq+s, Alt+SysRq+u, Alt+SysRq+s, Alt+SysRq+b (easy to remember
as S USB)...
Not sure what exactly does the second sync after umount does, but is
needed apparently.

Regards,
Kalin.