UDEV - Not Leaving Well Enough Alone

alupu at verizon.net alupu at verizon.net
Mon Nov 23 16:29:27 PST 2009


Alex:
>> In the past, I was able to avoid creation
>> of unnecessary fd nodes.

Mike McCarty:
> In what sense unnecessary?
> Do your floppy drives not support those modes?
> There are tools which use the name of the device
> to select their mode of operation, and
> if you don't have a /dev node for that then they
> don't operate properly or even refuse to operate.
 ...
> I have encountered some which don't respond to what
> setfdprm does.

Hello Mike,
Thank you very much for your comments.

SHORT ANSWER
"Unnecessarily" from _my_ standpoint (obviously limited).

GORY DETAILS (in the order of increasing blood content)
1.  I do happen to have 'setfdprm', a carry over from
my original 2005-LFS system (on two machines - mirrored)
I've never used it nor do I foresee a need in the future.
No "mode" tools have ever failed on me, to my recollection.
Not that I ever used them consciously.

2.  For reference
01/20/2005      util-linux-2.12q        My setfdprm version
09/23/2005      util-linux-2.12r        Last of the series

The new "ng" series no longer contain 'setfdprm'
(by accident??):
09/10/2008      util-linux-ng-2.14.1    My version
09/07/2009      util-linux-ng-2.16      Latest non-rc

3.  Each of my two machines has a garden-variety floppy.
In Linux, I use them regularly with various size floppies,
360, 720 but, by far, 1440.  The numerous floppy drives
I've encountered just accepted/read the floppies.
Never a need to change the mode.
The last thing is to start a flame here;  I still see a
need for floppies on Linux due to the relatively small
sizes of files in need to be quickly sneakered among
machines.
I also understand the people who rave and rant against
using floppies at this day and age (God Bless'em).
I would also understand someone who still uses/needs
"cmos"/setfdprm/modes if I ever hear a real case in the
developed world (Got Bless her too, in advance).

4.  As I said, I'll personally be just fine with only
'/dev/fd0' for the rest of my Linux life.
HOWEVER, modes or no modes, my actual
POINT has been that the situation when "last_rule"
existed, while ugly, was manageable for me.
Once that OPTION was arbitrarily eliminated
("Its use breaks too many things ...") everything
becomes a nightmare (in relative terms :) for me,
with the ATTRS{cmos} rule imposed by the UDEV
developers (and reinforced by LFS) as a default.
That's why I hoped someone might know another
"semi-permanent" workaround in the 147+ world.

5.  My bad luck (I suppose, like many others who use
a floppy as a floppy - like me) is that the mostly
intractable by mere mortals, the '/sys' file system,
has a "file" '/sys/devices/platform/floppy.0/cmos'
with a mysterious content, one byte of value ASCII 4.
This makes my system(s) eligible for the famous
"cmos" rule, whether I like it or not, or whether
99% of the population couldn't tell a "CMOS" floppy
drive from a hole in the ground.

Thanks again,
-- Alex

PS. If someone (a System Administrator?) could help
and delete my FIRST post (the one without the
"Hello NOTE" disclaimer.), that'd mean a lot to me.
It's obviously been a disgrace and a confusion.
I was testing if my Verizon (as opposed to GMail)
had acceptable plain text I could use.
Unfortunately, the self-test went awry and the draft
escaped into the world wide web.



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