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Re: [PLUG] More SCSI Weirdness
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As far as I know it's terminated at both ends. The card reports auto
termination and I have an active terminator on the external drive case.
On Sun, 9 Dec 2007, Eric wrote:
> Active termination is better than passive but both exist.
>
> Here's what I know is a nutshell:
>
> Both ends of the bus must be terminated but no other device in the bus should be
> terminated.
>
> Example 1:
>
> T---------+---------+----------+-------+-------T
> SCSI drive drive drive cable end
> adapter
>
> Alternatively, last drive has termination set on:
>
> T---------+---------+--------+-------+-------T
> SCSI drive drive drive
> adapter on cable end
>
> (+) is connector
> (T) indicates termination point.
>
> Incorrect or missing termination causes "ringing" on the bus and might cause
> this kind of error.
>
> Eric
>
> jazzman@exdomain.org wrote:
> > Both the card and case claim auto termination, but I also have a
> > terminator (marked active terminator... is there a "passive" kind?) that
> > I've tried... same behavior...
> >
> > On Sun, 9 Dec 2007, Eric wrote:
> >
> >> Hey, I'm no SCSI expert but this has a certain "oddness" that might be explained
> >> by improper SCSI bus termination.
> >>
> >> Have you checked that?
> >>
> >>
> >> Eric
> >>
> >>
> >>
> >> jazzman@exdomain.org wrote:
> >>> Ok, so I think I may have some more info on the weird drive behavior I was
> >>> seeing with my scsi array.
> >>>
> >>> I tried the drive array on a second machine, different OS (Fedora 5) but
> >>> the machine behaves similarly (doesn't always detect ALL of the drives on
> >>> each boot... the scsi drives randomly pop in and out of existence on each
> >>> reboot). The only thing I did notice is that each machine has the SAME
> >>> scsi card (tekram DC395x) and that when the drives disappear on the FC5
> >>> machine I get the following error message flooding the logs:
> >>>
> >>> dc395x: QUEUE_FULL for dev (0X-0)
> >>>
> >>> where X is the scsi ID of the first "missing" drive.
> >>>
> >>> Does anyone know anything good/bad about this card? It was cheap when I
> >>> bought it, but I'm hesitant to go buying new cards/cables and such without
> >>> knowing for sure. If this is a "could be anything" type of problem I have
> >>> a feeling the scsi case and it's drives end up on ebay befoer long...
> >>>
> >>> any thoughts?
> >>>
> >>
> >
> > ___________________________________________________________________________
> > Philadelphia Linux Users Group -- http://www.phillylinux.org
> > Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
> > General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
>
>
>
___________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
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