Re: Journaling pointless with today's hard disks?

From: Ian Stirling (root@mauve.demon.co.uk)
Date: Mon Nov 26 2001 - 20:01:19 EST


>
> At 12:49 AM +0100 11/27/01, Martin Eriksson wrote:
> >I sure think the drives could afford the teeny-weeny cost of a power failure
<snip>
> converter, which is expensive. If you simply detect a drop in dc
> power, there simply isn't enough margin to reliably write a block.
>
> Years (many years) back, Diablo had a short-lived model (400, IIRC)
> that had an interesting twist on this. On a power failure, the
> spinning disk (this was in the days of 14" platters, so plenty of
> energy) drove the spindle motor as a generator, providing power to
> the drive electronics for several seconds before it spun down to
> below operating speed.

I have a (IIRC) elantec databook from 1985 or so, that I've found chips in
disks from the MFM/RLL PC era.
These are motor driver chips aimed at PCs, which support generation
using the motor.
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This archive was generated by hypermail 2b29 : Fri Nov 30 2001 - 21:00:24 EST