Re: De-activate a swap partition - I don't believe it!

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On Wednesday 22 March 2006 03:52, Mike McCarty wrote:
>Christofer C. Bell wrote:
>> I don't know what the HOWTO says about swap, but if you're going to
>> be hitting swap a lot, you want it on the inside tracks of the disk
>> where the sectors are closer together physically (because they're
>> smaller). Less space traveled by the disk head = faster access
>> times.
>
>I don't either, but what you just wrote is wrong wrong wrong. Track to
>track spacing is the same all across the disc. And there are the same
>number of sectors per track as well. The disc rotates at a fixed rate,
>so the same number of sectors pass under the head no matter where the
>head is on the disc.

No. I explained that before. Its the same number of sectors per second, 
but the inner tracks have less velocity, hence fewer actual sectors per 
track.  Because the sectors are the same physical length in terms of 
the velocity of the disk, and they will occupy a larger angular space 
on the inner tracks, there is room for fewer sectors per track on the 
inner tracks. This has been true since about the days of the stX38 mfm 
drives of nearly 20 years ago, so please stop confusing the issue with 
false information.

And yes, the signals carrier frequency does go down due to the lower 
surface velocity of the inner tracks, the data decoders can track that 
25% change just fine, its the magnetic domains per inch that can be 
detected which is the limiting factor.

The track spacing from track to track is also fixed, and today is 
recalibrated by the drive at frequent intervals in oder to compensate 
for the thermal growth/shrinkage of the disk as it warms and cools.  

This is done any time the drive thinks its not getting enough signal 
from the track, which in borderline drives can be often enough to 
notice the seek noise.  Drives that do that are suspect, and should 
have backups made of them religiously.

-- 
Cheers, Gene
People having trouble with vz bouncing email to me should add the word
'online' between the 'verizon', and the dot which bypasses vz's
stupid bounce rules.  I do use spamassassin too. :-)
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message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.


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