> I am not sure about this, i understood that "sync" was performed by
> "umount" so that buffers were flushed before the device was actually
> unmounted

umount should flush all buffers first, then perform the umount. However,
I believe this doesn't happen in the case of fatXX filesystems, so
unless you manually sync before umount you end up with a corrupted
filesystem on your usb stick (or doze partition).

The mount option "sync" causes all writes to the device to be performed
synchronously, i.e. there's effectively no buffering used. That's why
it's slow, but if you want to be able to unplug the USB stick at any
time without explicitly flushing buffers (or unmounting), you will have
to mount with option "sync" because if you don't, by the time the kernel
knows the device is unplugged, flushing buffers is a thing of the past
and you've lost your data.

The command for flushing buffers to disk is also called sync, don't
confuse the two.

Volker

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Volker Kuhlmann                 is possibly list0570 with the domain in header
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