From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <3257ee4d43273f8ac3ecfc6a78595e85@plan9.bell-labs.com>
Date: Fri, 30 Jun 2006 14:28:00 -0400
From: jmk@plan9.bell-labs.com
To: 9fans@cse.psu.edu
Subject: Re: Re: [9fans] Any one going to change to sata disks?
In-Reply-To: <6e35c0620606300909m408c48dcr37150b4e5a69686e@mail.gmail.com>
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I had to go back and read the thread to see how we got here:

	1) some piece of hardware which no real effort has been made
       to programme doesn't work right;
	2) familiar discussion about hardware, drivers, documentation;
	3) suggestion is to buy a much more expensive piece of
	   hardware with similar lack of documentation.

We haven't invested any effort in making the free hardware we
get on almost every motherboard work, maybe someone should try.

I think we need to focus here.

On Fri Jun 30 12:10:12 EDT 2006, knapjack@gmail.com wrote:
> On 6/29/06, geoff@collyer.net <geoff@collyer.net> wrote:
> > Even omitting the firmware image (tw_cl_fwimg.c), which is also vast,
> > that's over 10,000 lines of C for a disk driver, 4,223 lines of which
> > is the `OS Layer' (tw_osl_*).  Our largest Plan 9 driver (other than
> > devsdp.c), which is also one of the largest source files, is
> > pc/sd53c8xx.c, which weighs in at 2,264 lines.  I think *that's* huge=
,
> > but apparently the NCR controllers are messy.  Maybe it's possible to
> > `just' write an `OS Layer' for the twa driver, but do we really want
> > to include a driver that's as big as a V6 Unix kernel (`free Unix
> > kernel with every Plan 9 distribution')?
>=20
> Good point.  Strike one. :)
>=20
> How about the LSIs?  This looks promising:
>=20
> ( from http://linuxmafia.com/faq/Hardware/sata.html#lsilogic )
>=20
> "LSI Logic MegaRAID SATA 150-4 (four ports) and 150-6 (six ports)
> Serial ATA RAID Host Adapters =EF=BF=BD real hardware RAID. Work with 2=
.4.x
> kernel's megaraid2 driver (same one as for SCSI). Cards use an Intel
> GC80302 dedicated I/O processor. This chipset, under its former AMI
> brand name, has had a long and excellent history with SCSI gear.
> Optional battery backup unit is available for the model 150-6 card's
> cache, for more reliable operation in the event of power loss, etc.
> These cards should not be confused with the low-end LSI Logic MegaRaid
> SATA 150-2 card."
>=20
> Skimming for source now to do the same size comparison....
>=20
> -Jack