Subject: Re: Another changer, another changer problem
To: Todd Whitesel <>
From: Curt Sampson <>
List: current-users
Date: 10/09/1998 00:39:34
On Thu, 8 Oct 1998, Todd Whitesel wrote:

> Much of my interest in this is because I see many things _beyond_ it. I'd
> like a kernel capable of LKM'ing many of its device drivers, so I do not have
> to reconfig+reboot when I borrow a new USB device for a few days.

That's fair enough. But this Sort of configuration is not something
I'd use on a production server, which is what Greg appears to be
making his argument about. On a production server, which doesn't
change much, I want everything in the kernel and firmly wired down.

> You're glossing over the mandatory MAKEDEV step which is occasionally needed.

Well, yes, because I can gloss over it. There's nothing to think
about when you do a `MAKEDEV sd7'; it just makes it and that's it.
The work as to where the drive is and where it's mounted are done
in the kernel config and fstab, respectively.

> The two are information-equivalent. The symlink-nest system is operationally
> a superset of the config-file system.

Well, not exactly. The config-file system has the advantage that
once the system is up and running, the device mappings cannot
change. An accidental re-run of a configuration script or removal
and incorrect re-making of a link or two can cause problems; these
hard-to-detect problems don't happen with kernel configs. (A reboot
is pretty easy to detect. :-)) And keep in mind that on the sorts
of systems these are aimed at you're not talking about a couple of
wd devices; you're talking about two or three SCSI controllers and
a dozen or more SCSI disks. That's not the kind of configuration
information you're likely to remember for very long, especially
after the server's been running continuiously for a few months..

> Perhaps it would make sense for the /dev directory to be read-only most of
> the time, so it's harder to screw yourself by blowing away devices. That
> would help avoid mistakes, period.

That's true.

Curt Sampson  <>  604-257-9400    De gustibus, aut bene aut nihil.
Any opinions expressed are mine and mine alone.
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