Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 16 May 1995 08:18:07 -0400 (EDT)
From:      Peter Dufault <dufault@hda.com>
To:        davidg@Root.COM
Cc:        current@FreeBSD.org
Subject:   Re: big files written to scsi harddisk got corrupted
Message-ID:  <199505161218.IAA24599@hda.com>
In-Reply-To: <199505161039.DAA01603@corbin.Root.COM> from "David Greenman" at May 16, 95 03:39:18 am

next in thread | previous in thread | raw e-mail | index | archive | help
David Greenman writes:
> 
> >as on the Syquest. I presume this is a bug in FreeBSD as the drive is 
> >new and the controller is known to have worked flawlessly in another machine.
> >In case you need it here is my configuration:
> >
> >Adaptec 1542 A SCSI controller (I use its floppy disk controller, too)
> 
>    The Adaptec 1542A is known to corrupt data for DMA's that are larger than
> 16Kbytes. FreeBSD uses I/O clustering both in the file I/O system and in the
> VM system and DMA's are frequently larger than 16Kbytes. There are apparantly
> some versions of the 1542A that don't have this problem, but every one that
> I've tested does. If you upgrade the controller to a 1542B, the problems
> should go away.
> 

Can we just put in a minphys for 16K for the 1542A?

It is easy to tell when an adapter says it is a 1542A.  We can add
a flag argument to disable it if you have a known working board or
a clone of some sort that says it is a 1542A.

This is what I plan to do once I get a computer I can actually test
it on.  I don't like making changes I can't test.

Peter

-- 
Peter Dufault               Real Time Machine Control and Simulation
HD Associates, Inc.         Voice: 508 433 6936
dufault@hda.com             Fax:   508 433 5267



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199505161218.IAA24599>