AW: DOC vs. IDE

[Dave Dworin]

I doubt if CF is reliable to replace IDE disks. I own a CF digital camera 
and have experienced data loss. It seems that data loss/file corruption is 
quite common on CF. Any different experience?

Dave






>From: "Richard A. Smith" <rsmith at bitworks.com>
>Reply-To: "Richard A. Smith" <rsmith at bitworks.com>
>To: "linuxbios at clustermatic.org" <linuxbios at clustermatic.org>
>Subject: Re: AW: DOC vs. IDE
>Date: Wed, 23 Oct 2002 16:28:28 -0500
>
>On Wed, 23 Oct 2002 14:28:23 -0600 (MDT), Ronald G Minnich wrote:
>
> > On Wed, 23 Oct 2002, Christopher Bergeron wrote:
> >
> > > That actually sounds like a brilliant idea.  I wonder if anyone on the
> > > list can confirm performance... does the CFcard appear as a standard 
>IDE
> > > disk or is there a driver or anything necessary?
> >
> > we're doing it here on the PCM-5823-A2 geode cards. We use CF as 
>/dev/hdc,
> > there is no /dev/hd1. Works fine.
> >
>
>I'll pipe in a little bit of personal experience here.  If you are
>_just_ using a CF with an IDE adapter then all is well and things
>will work great.
>
>During bringup and debug though its nice to have a big HD with a full
>linux distribution on on it so you can develope on your target.
>
>However if you are using a CF _and_ a normal IDE drive you may run
>into a gotcha.  In the 2.2 linux IDE code there are clauses that if a
>CF device is dectected on hda it will NOT probe for hdb.  Same goes
>for hdc and hdd.  There is no output telling you its skipping it
>either.  Apparently there were some early CF devices that did some
>funky stuff with the diag signal (drive dection) and Andre (the 2.2
>IDE maintainer) chose to blacklist all CF devices.
>
>The fix is to feed the kernel some parameter like ide0=flash or
>something similar to make it go ahead and probe.
>
>I haven't looked at the 2.4.x IDE code so I don't know if it carried
>over or not.
>
>But if you mysteriously don't have an hdb with a CF hooked up in your
>system go check the IDE probing code before you pull you hair out
>trying to figure out whats wrong with your hardware like I did.
>
>--
>Richard A. Smith                         Bitworks, Inc.
>rsmith at bitworks.com               479.846.5777 x104
>Sr. Design Engineer        http://www.bitworks.com
>
>
>_______________________________________________
>Linuxbios mailing list
>Linuxbios at clustermatic.org
>http://www.clustermatic.org/mailman/listinfo/linuxbios


_________________________________________________________________
Unlimited Internet access for only $21.95/month.  Try MSN! 
http://resourcecenter.msn.com/access/plans/2monthsfree.asp