Subject: Re: kern/1781: 'magic' symbolic link expansion
To: Arne H. Juul <>
From: Peter Galbavy <>
List: netbsd-bugs
Date: 11/23/1995 05:29:31
> It's not optional.  Each and every name lookup do that extra little
> check to see if we should expand magic in the first place.  If it's made
> a kernel option which is *not* enabled in standard configuration, then
> it's "just" extra cruft (aka "optional facility").  I'd rather have cruft
> like i386-specific bounce buffer support, but for some reason that isn't
> "necessary" enough [see footnote].

I disagree. I think this is a great idea, and makes running a truly
multi-platform OS much, much easier. This includes "day to day" as well
as install time. Especially for diskless machines.

I doubt the overhead is much more than any other "special case" processing
happening now, and the lookups could be cached just as easily as any other.

As I mentioned in a private reply to Chris, I think that maybe this
should be extended to include other variables, and perhaps even
get a group of 'sysctl' variables to itself. This way you could
magically set "per system" variables. I don't think I said it quite
in these words however, but that is what I meant.

Try maybe:

	fs.magic.osname -> @osname = "NetBSD"
	fs.magic.sys_arch -> @sys_arch = "i386"

Then, some odd ones:

	fs.magic.local_0 -> @local_0

This could then let you "swap" installs for testing with a:

	sysctl -w fs.magic.local_1=test_usr

Where the root fs looks like:

	/usr -> /@local_1

or whatever. Just my @opinion = $0.02c worth :-)

Peter Galbavy                                 
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in Wonderland