WHY !!! ?

[Mihai T. Lazarescu]

On Sun, Sep 15, 2013 at 06:27:08PM +0200, Reindl Harald wrote:

> Am 15.09.2013 18:03, schrieb Jim:
> > On 09/14/2013 08:11 PM, Sam Varshavchik wrote:
> >> Do you explicitly unmount your flash drives, before yanking them out.
> > I have to admit that is the one thing I don't do
> 
> so answering with your subject in normal letters: why?

Indeed.  Linux uses (extensive) buffering.  Your write
command may return but the data be still in memory instead
of written on the drive.  If you disconnect it right away,
besides a corrupted file system you may find that your files
are incomplete or missing.

So, with FAT FS issue a sync and wait for it to return or,
much better, unmount (which forces a flush of the associated
write buffers).

Regarding the mount read-only, the kernel may decide to do so
if the FS has errors.  It should resume mounting it RW once
the errors are fixed.

Mihai