Re: disk head scheduling

Rik van Riel (riel@nl.linux.org)
Fri, 19 Mar 1999 13:22:11 +0100 (CET)

On Fri, 19 Mar 1999, Mark H. Wood wrote:
> On Fri, 19 Mar 1999, Ingo Molnar wrote:
> > On Thu, 18 Mar 1999, Yasushi Saito wrote:
> > > What I tried to implement was two-way elevator seeking (SCAN). In my
> >
> > the bigger problem is that dumber devices will just execute non-forwards
> > ordered requests. Most modern harddisks will either cache a full track, or
>
> Well of course a 2-way elevator should sort by *ascending* sector within
> descending track. I take it this is difficult?

Modern devices never give you the physical layout of the disk,
so yes, it is extremely difficult, if not impossible...

Rik -- Open Source: you deserve to be in control of your data.
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