[NTLUG:Discuss] Re: devfs and udev -- WAS: What is the deal with SuSE

[Bryan J. Smith]

On Fri, 2005-08-19 at 04:52 -0500, Leroy Tennison wrote:
> You brought up something I've been wondering about.  I had heard about 
> udev but don't know anything about it.  Can you explain briefly (or 
> point me to something which does):
> What was "wrong" with /devfs that caused it to be replaced

First off understand devfs and udev had the same goals.

It was just realized that a user-space /dev solution not only solved a
lot of issues with a kernel-space /dev filesystem, let alone got rid of
the fact that it was in the kernel where an unfinished solution could
cause it a lot of problems.  ;->

> How udev is different

I think the FAQ does a great job at this:  
  http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev-FAQ  

> What is so great about udev
> How does it affect me practically (where will I see/feel the differences).
> I don't want to be cynical but I'm not convinced that 'new' is 
> necessarily 'better'. 

That was the problem with devfs too.
udev gets that problem out of the kernel.  ;->

I know that seems like a circular reference, but it makes sense if you
understand all the issues that the approach of devfs already had, plus
the issues of putting it in the kernel added to it.

> A prime example is 'nslookup' being depreciated 
> and possibly being replaced with 'dig'.

Both of those are user-space.

udev is more about getting things out of the kernel that aren't finished
and were adding more constraints by being in the kernel anyway.


-- 
Bryan J. Smith     b.j.smith at ieee.org     http://thebs413.blogspot.com
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