[PLUG] fstab entry

[Galen Seitz]

On 08/30/15 16:55, Denis Heidtmann wrote:
> On Sun, Aug 30, 2015 at 9:04 AM, Galen Seitz <galens at seitzassoc.com> wrote:
...
>> Well, to my mind, commands like mdir and mcopy are about as routine as
>> it gets, but if you're keen to use the GUI, then mtools won't be of much
>> use.  I will point out that not mounting a floppy has at least the one
>> advantage that you avoid the possibility of corrupting the floppy by
>> ejecting it when it is mounted.
>>
>> galen
>>
> 
> I am often hesitant to post questions here because my ignorance and
> inexperience get laid bare.  I do not understand how not mounting provides
> that protection.  This lack of understanding is because I do not have a
> clear view of what happens when a device is mounted, and how the device is
> accessed without mounting.

When a filesystem is mounted, the linux will typically cache blocks of
filesystem data in RAM for performance reasons.  Blocks of data that
need to be written back to the device (aka dirty blocks) may sit in RAM
for multiple seconds before being flushed to the device.  This is one of
the reasons that graceful shutdowns are always preferred over pressing
reset or yanking the cord.  In the case of a floppy or USB drive,
ejecting or unplugging is the equivalent of yanking the cord.  There is
no opportunity for the system to write the data to the device, and
filesystem corruption is often the end result.

AFAIK, the mtools commands don't do any caching of writes.  When you get
the next command prompt after executing an mtool command, it is safe to
immediately eject the disk.  As described above, this is not true of a
mounted filesystem.

Hope this helps.

galen
-- 
Galen Seitz
galens at seitzassoc.com