12 Jan
2011
12 Jan
'11
1:24 p.m.
> In the context of a hard disk, though, a
'cylinder' means all the tracks
> that can be accessed without moving the heads. So if you have 4 data
> surfaces (such as the ST412), a cylinder contains 4 tracks. In an RK07,
> which has 3 data surfaces and 1 servo surface, as cylinder it 3 tracks.
> And so on.
Ahh, I see. Thanks for that Tony.
The name 'cylinder' comes, of course, from the image of a cylinder
paralel to the drive spindle going trhough all the platters. The
intersecion of that 'cylinder' and the platters (both sides) are the
tracks that you can access without moving the heads.
Now, if you had a positioner that could only move half the distance from
outside rim of the platter to the spindle, but you had 2 heads per
surface suitbleyoffset (so that you could access 2 tracks on each surface
without moving the psoitoned) then I would claim that both of thos tracks
were part of the same sylinder. For example, if you had 4 data surfaces
(and thus 8 hards in this drive), I would say that a 'cylinder' contains
8 tracks, even though the arrangement of said tracks doesn't look like a
physical cylinder any more.
You (or more accurately, I) learn something new every
day - especially on
this list :)
Actually, I learn several things from this list every day.
-tony