On Mon, 14 Jan 2002 02:19:15 +1130
Mike Andrew <[EMAIL PROTECTED]> spewed into the bitstream:
> On Sun, 13 Jan 2002 23:36, David A. Bandel wrote:
>
> > > modern distros deprecate the use of srX, get rid of them, literally.
> > > Promise from me that you can do no harm by deleting them.
> >
> > What's your source for this?
>
> /usr/src/linux/Documentation/devices.txt plus
That's what I get for not reading every word of every piece of
documentation with every new relaese. now I have to wonder when this
happened. :-(. OTOH, if I spent all my time rereading every single
document with every single release of every single package, I might be up
to reading in kernel version 1.2.10 about now. Maybe up to 2.2.18 in
2005.
>
> latest releases of most Distros (RH7.1/2 eg) only have /dev/scdX nodes.
> not srX nodes.
Most of what RH does is wrong, so don't use them as a measure of anything.
>
> >I run 2.4.17 w/ devfs
>
> all bets are off. devfs is a good idea, badly implemented, attrociously
> documented. It doesn't work with the LABEL=/ statement in /etc/fstab
If you have something better, I know lots of folks who would like to hear
your idea of how to do it. The reason for devfs is the explosion of
devices and the limited major/minor numbers available. In fact, devfs is
supposed to do away with the device numbers problem because there aren't
enough numbers for every device in the world. While you may not have but
a few devices connected to your system, if you had one that either didn't
have a major/minor because there were no more, or because another device
you're using is using the major/minor this new device needs, you're SOL
(sorry, out of luck).
>
> >when I modprobe ide-scsi then sr_mod,
> >the only devices created are sr0 and sr1.
> >These devices are created dynamically by sr_mod.
>
> Being pedantic, modules don't do this. devfs intercepts the registration
> and makes (and destoys) nodes on the fly. It picks up on the internally
> named 'sr' labels because, by convention, the names of device drivers
> are associated, programatically, with /dev/names. sr_mod, is an
> unfortunate choice.
so you need to tell whoever owns the sr_mod module that he's got to rename
is scd_mod because he's wrong -- no?
>
> Ignoring devfs for the moment, the only thing any driver, and any
> application, looks for is major / minor numbers, you can call the thing,
> and address the thing, as /dev/elephants for all that it matters. (it's
> just a lookup to the major/minor number).
yes, I know how major/minors work (currently). But that's also their
drawback. While I don't call any device foo, I have created device nodes
with this name just to show how it works to others.
>
> kernel messages invoked by sr_mod refer to it's device nodes as sr0 ...
> etc. BUT, these are hardwired internal printk messages of sr_mod.
> Popular useage these days is /dev/scd0.
So, the guy that programs sr_mod is as lost as I am (or hasn't read the
recent documentation changes and/or doesn't take RH as gospel).
>
> Regardless, the point being is that both names /dev/scdX AND /dev/srX
> mean the same thing, they are both the same major minors and cause added
> confusion in an already confused and idiotic scsi node tree. ( I am
> referring to both the dynamic assignment of /dev/sxx anything, and the
> tree jumps to accomodate a squillion scsi minor nodes).
No, it doesn't. You can't create that many device nodes because of the
limitation of the major/minor numbers.
>
> If it were not recommended to use scdX, and, if distros hadn't already
> pre-empted this by removing /dev/srX nodes, I would just as emphatically
> reverse my stance and remove scdX anything. Whatever whichway, the
> duality causes problems. (witness the screams in /etc/fstab by many
> users)
>
> To be truthfull David, I hadn't considered devfs, it's an added wrinkle
> to the mess.
I've been using devfs since it came out. I prefer it. It may not be
perfect, but it's a damn site better than creating thousands of useless
device nodes (which, BTW, take up inodes/disk space). On my personal
distro (mine, Chiriqui Linux, the one I created which boots from a CD and
runs in RAM mounting /usr from the CD) uses devfs -- or I would have to
create each device by hand for just what I need or I'd waste precious
space).
Sure would like to hear your idea of a replacement for devfs.
Ciao,
David A. Bandel
--
Focus on the dream, not the competition.
-- Nemesis Racing Team motto
Internet (H323) phone: 206.28.187.30
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