mkfs and disk performance

[Peter Brouwer]

 In article <3295 at segue.segue.com> jim at segue.segue.com (Jim Balter) writes:
>In article <628 at ssp2.idca.tds.philips.nl> pb at 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.

I think you are confused by the term gap.
It is also used in disk format layout definitions. 
In unix it has the meaning as I described it. Info was retrieved from the 
sources of mkfs and fsck.
















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