Cdrom drive access question

[Jeffrey Wong]

The periodic reading on your SCSI cdrom drive sounds like a SCSI bus
reset.  The last time I saw a system with frequent bus resets it turned
out to be a termination problem, so the first place I'd check is
there.  If you are using a passive terminator (unless it is actually
labeled as and active or force-perfect terminator its probably passive,
its the cheapest design), passive terminators only work reliably for
low speed scsi devices, and then only for a short scsi chain.  You might
consider getting an active terminator and trying that.  I believe IC
supply sells them for something like $30, and even if you don't need it,
I'd generally recomend it for any scsi system.  In any case, prolonged
usage of a badly terminated scsi chain can cause the controller to
become flaky, which may be whats causing your lockups.

Jeff

On Tue, 5 Feb 2002, Dean Fujioka wrote:

> Charles,
> Thanks for the reply.  Unfortunately my controller only has one interface,
> which has the CDrom drive and a 100mb zip drive on it.  I have two hard
> drives, both IDE on the primary channel. My computer will now not boot into
> linux very stably, and freezes causing me to run fsck manually over and over
> again.  I've unplugged the cdrom and was able to dmesg, and got something
> I/O error on sba 08:00 something or other. I can post it if you think it
> would help, but it might take some doing, as I'm having trouble just keeping
> everything running at this point. I didn't get to check /var/log/messages
> yet, but will try.
> thanks,
> dean
> 
> 
> ----- Original Message -----
> From: <cpaul at telemetrybox.org>
> To: "Linux & Unix Advocates & Users" <luau at maile.hi.net>
> Sent: Tuesday, February 05, 2002 8:25 AM
> Subject: [luau] Re: Cdrom drive access question
> 
> 
> > If your SCSI controller has two interfaces, try putting your CDRom on the
> (slower) interface seperate from your Hard Drive.  Short of that, check your
> /var/log/messages or dmesg to see if there are any periodic bus errors which
> might be associated with your performance hiccups.
> >
> > aloha,
> > charles
> >
> >
> > On Mon, Feb 04, 2002 at 10:43:31PM -1000, Dean wrote:
> > > I was wondering if anyone has experienced issues with cdrom drives that
> > > check for a cd every minute or so. Whenever this happens, the screen
> > > freezes temporarily and then comes back.  The thing is, though that only
> > > the scsi cd-writer (yamaha 4x on a adaptec 2940AU) is having the
> > > problem, while the cdrom on the ide channel does not do this. Is there
> > > any way to disable this? please point me to a man page or something...
> > > just typing drives me nutz.
> > >
> > > thanks,
> > > dean
> > >
> > >
> > > ---
> > > You are currently subscribed to luau as: cpaul at telemetrybox.org
> > > To unsubscribe send a blank email to $subst('Email.Unsub')
> >
> > ---
> > You are currently subscribed to luau as: surfdean at hawaii.rr.com
> > To unsubscribe send a blank email to $subst('Email.Unsub')
> 
> 
> ---
> You are currently subscribed to luau as: jmwong at hoku.net
> To unsubscribe send a blank email to $subst('Email.Unsub')
>