On Thu, 26 Aug 2021 19:20:06 +0930
Tim via users <users(a)lists.fedoraproject.org> wrote:
On Wed, 2021-08-25 at 21:21 -0700, Geoffrey Leach wrote:
> I have a script that mounts an MP3 device, copies files and umounts.
> As I have counted on the umount to hang until the data transfer is
> complete. That has worked fine until recently. Now the umount
> finishes, leaving much of the data uncopied.
Just to be very clear:
Have you issued a string of commands, so that you expect all the copy
commands to be executed in series before the unmount command is
issued? Write-caching can be a problem, though the system shouldn't be
unmounting before the cache is flushed.
Or have you issued the copy and unmount commands, and hope that the
actual copying will hold the unmounting at bay until finished?
Parallel commands can be a problem, if you expect them to be issued in
one order, but they don't quite get queued up in the way you expect.
This sounds rather similar to the problem I've seen with with USB
flashdrives, and SD cards, where I've seen the message pop up on the
screen telling me it's okay to unplug the drive, but clearly the data
transfers actually haven't yet finished. In my case, that would be
some time after dragging and dropping files onto the destination, then
waiting what seemed a reasonable amount of time before I right-clicked
to eject or unmount the device
copy ... copy ...umount