Subject: Re: /etc/rc.d/ runs slowsly
To: None <firstname.lastname@example.org>
From: Greg A. Woods <email@example.com>
Date: 04/12/2000 17:10:15
[ On Tuesday, April 11, 2000 at 23:09:32 (+0200), Wolfgang Rupp wrote: ]
> Subject: Re: /etc/rc.d/ runs slowsly
> Greg A. Woods wrote:
> > Will /usr fit if you don't install comp, games, man, etc.?
> Maybe. What is the gain? As it is now, I can get the machine up
> standalone if I need, and everything for /usr is in one place,
> identical for all machines and easy to maintain.
It depends on the purpose of the machine I guess. I can't quite imagine
why you'd want some of that stuff on an otherwise limited machine,
unless of course it's the only one of its kind in your network (in which
case all kinds of assumptions go out the window anyway).
I was almost to the point where I was going to union-mount an NFS copy
of /usr so that I could get at the compiler but I finally figured out
how to tweak /etc/mk.conf so that I could do "make install" from an
NFS-mounted build directory without having to do so. In this particular
case I definitely do not want the compiler permanently installed on my
firewall machine anyway! (and I can do without games and manual pages)
> The RD53. I have not measured that, though, so that statement may be
> biased by my dislike of several minute long boots over the network.
> Swap is definitely faster locally, the NFS server does not like three
> machines swapping to it.
> I still fail to see the light why /usr on root gives me an advantage.
There might not be any advantage to having /usr on the root filesystem
-- it depends on your exact circumstances and needs.
In my experience with diskless Sun-3's and Sparc-1's the NFS is usually
faster for filesystem accesses than most disks that would be too small
to accomodate a full system install anyway, though indeed swapping to a
local disk or two is indeed usually faster than NFS no matter how slow
the disks. I don't boot my machines frequently enough to be concerned
about the boot time one way or another, but I suppose if I did I might
want my kernel to load off the local disk (but still mount / from NFS).
In the past there was a window of time where affordable CPUs were much
faster than affordable disks of comparable speed and as a result it was
highly advantageous to spread as many filesystems over as many spindles
(and controllers and buses) as possible. In this case having /usr on a
separate spindle was a big advantage. In those days I even mounted
/usr/lib (and of course /usr/spool and /usr/mail) on a separate spindle
on some machines.
In any case I'm fairly sure that anyone who spends even a relatively
small amount of time using a system in single-user mode will quickly
come to appreciate having the stuff in the /usr hierarchy permanently
Greg A. Woods
+1 416 218-0098 VE3TCP <firstname.lastname@example.org> <robohack!woods>
Planix, Inc. <email@example.com>; Secrets of the Weird <firstname.lastname@example.org>