Re: File system compression, not at the block layer

From: Måns Rullgård
Date: Fri Apr 23 2004 - 15:46:08 EST

"Richard B. Johnson" <root@xxxxxxxxxxxxxxxxxx> writes:

> On Fri, 23 Apr 2004, Joel Jaeggli wrote:
>> On Fri, 23 Apr 2004, Paul Jackson wrote:
>> > > SO... in addition to the brilliance of AS, is there anything else that
>> > > can be done (using compression or something else) which could aid in
>> > > reducing seek time?
>> >
>> > Buy more disks and only use a small portion of each for all but the
>> > most infrequently accessed data.
>> faster drives. The biggest disks at this point are far slower that the
>> fastest... the average read service time on a maxtor atlas 15k is like
>> 5.7ms on 250GB western digital sata, 14.1ms, so that more than twice as
>> many reads can be executed on the fastest disks you can buy now... of
>> course then you pay for it in cost, heat, density, and controller costs.
>> everthing is a tradeoff though.
> If you want to have fast disks, then you should do what I
> suggested to Digital 20 years ago when they had ST-506
> interfaces and SCSI was available only from third-parties.
> It was called "striping" (I'm serious!). Not the so-called
> RAID crap that took the original idea and destroyed it.
> If you have 32-bits, you design an interface board for 32
> disks. The interface board strips each bit to the data that
> each disk gets. That makes the whole array 32 times faster
> than a single drive and, of course, 32 times larger.

For best performance, the spindles should be synchronized too. This
might be tricky with disks not intended for such operation, of course.

Måns Rullgård

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