Path: utzoo!attcan!uunet!zaphod.mps.ohio-state.edu!usc!jarthur!elroy.jpl.nasa.gov!sdd.hp.com!mips!sgi!daveh@xtenk.asd.sgi.com
From: daveh@xtenk.asd.sgi.com (David A Higgen)
Newsgroups: comp.sys.sgi
Subject: Re: slow boot-time fsck -y -D, invoked by mount(!)
Message-ID: <73531@sgi.sgi.com>
Date: 29 Oct 90 20:14:03 GMT
References: <1990Oct28.073438.8627@utstat.uucp>
Sender: guest@sgi.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 21

In article <1990Oct28.073438.8627@utstat.uucp>, geoff@utstat.uucp (Geoff Collyer) writes:
> We have an SGI 4D220 with 64Mb of main memory running Irix 3.2 with a
> built-in ESDI disk and 4 SMD disks (3 Fujitsu Eagles and 1 Swallow) on a
> Xylogics 754 (yer basic adequate computer).  The SMD drives come from an old
> Sun 3/160, where the Eagles were on a Xylogics 451 instead.  One might
> naively expect that the boot-time fscks would run faster on the SGI due to
> having two, much faster, processors and a faster SMD controller, yet the SGI
> takes 45 minutes (elapsed time) to check these drives, while the Sun took
> about 15 minutes.  The obvious difference is that the Sun used /etc/preen,
> which in turn invokes one "fsck -p" per drive and runs all the fsck's in
> parallel, whereas the SGI fscks each filesystem separately, one after the
> other with no parallelism at all (truly Unparalled Performance (TM)!).  I
> sought to change this suboptimal state of affairs.

I'm currently in the midst of a major overhaul of fsck which will appear
in the next release. I've been able to make a speed improvement of a factor
2 to 2.5 in the program itself, and there will be logic added to do
parallel fsck's during bootup.


			Dave Higgen (daveh@xtenk.asd.sgi.com)