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From: Terry Lambert <terry@lambert.org>
Message-Id: <199510031741.KAA01408@phaeton.artisoft.com>
Subject: Re: RAID solutions for FreeBSD
To: gibbs@freefall.FreeBSD.org (Justin T. Gibbs)
Date: Tue, 3 Oct 1995 10:41:11 -0700 (MST)
Cc: terry@lambert.org, gibbs@freefall.FreeBSD.org, rsnow@txdirect.net,
        nc@ai.net, questions@freebsd.org
In-Reply-To: <199510030332.UAA07368@aslan.cdrom.com> from "Justin T. Gibbs" at Oct 2, 95 08:32:55 pm
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> >I *know* that 1-3 can be done without sequencer level coding.  I suspect
> >that 4-5 can be too, albiet at a *very* high cost in processing time.
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >Check out the ZEBRA FS papers (RAID II).
> 
> I read it last year.  It would be a total waste to do the parity
                                                            ^^^^^^
> calculations on the host processor when the card will do this for
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> you (assuming I can get docs).

I know, I know -- it's just that the idea of a software-only soloution
is very attractive.  Putting the calculations in the sequencer code
may be more efficient, but it's wholly unportable.

Well, unless we write a high level sequencer language and "compile" it
to NCR + Adaptec, etc.  I don't know how similar the sequencer instruction
set is; probably not very.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.