Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!randvax!segue!jim
From: jim@segue.segue.com (Jim Balter)
Newsgroups: comp.unix.i386
Subject: Re: mkfs and disk performance
Message-ID: <3295@segue.segue.com>
Date: 29 Aug 90 02:31:45 GMT
References: <1990Aug21.050638.15737@cimcor.mn.org> <536@fciva.FRANKLIN.COM> <628@ssp2.idca.tds.philips.nl>
Reply-To: jim@segue.segue.com (Jim Balter)
Organization: Segue Software, Inc. - Santa Monica, CA. +1-213-453-2161
Lines: 11

In article <628@ssp2.idca.tds.philips.nl> pb@idca.tds.philips.nl (Peter Brouwer) writes:
>To be precise, the gap determines the way the free block space is organised.

That is neither precise nor correct.  The gap is the rotational gap,
which is the offset between the logical track start from one track to another.
This offset is to account for track-to-track seek time; if it is just right,
the next block will be under the read head just as it settles over the track. 
It has nothing to do with free space, unless your system has taken this value
over for something other than its original purpose.  The gap was important
back when UNIX ran off of RK05's; modern disk controllers should optimize
track formatting for contiguous I/O.