Re: Desperate situation

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On Wed, 2006-02-15 at 10:54 +0900, Joel Rees wrote:
> 2006-02-14 (火) の 22:34 +1030 に Tim さんは書きました:
> > On Tue, 2006-02-14 at 11:34 +0900, Joel Rees wrote:
> > > The people that sold me the box and the controllers were pleased that
> > > I didn't have any particular problems using the slave interface on
> > > that particular motherboard. (They had specifically warned me that
> > > there would be no guarantees on it.)
> > 
> > Just to be clear, a slave drive is on on the same cable as another
> > (master) drive.  If you have two IDE ports on the interface one isn't a
> > master and the other slave, it's just two ports.
> 
> Yeah, my post wasn't very clear. Two channels per controller,
> master/slave device per channel, master device should be on the
> connector closest to the controller because of noise issues and that's
> why some half-bright got the idea that it should just be left up to
> cable select anyway, ...
> 
NOTE:  If you have a CS cable putting the master in the middle probably
will not work.  The CS cable has the master connector at the end and the
slave in the middle.

I have always been told (even in hardware schooling) that you should
always have a device at the cable end to prevent 'ringing' and noise
caused by signal reflection from an unterminated cable end.  This is
mandatory on SCSI and highly recommended on IDE cabling. (it is
sometimes unnecessary, not because the problem does not exist, but
because the data transfer is so [relatively] slow that some interference
does not impact performance seem by the user).
I never install a single device on a cable unless it is connected to the
end of the cable.  This by default makes the single device the master,
and thus implies a reason for putting the master connector at the end of
the cable.

> And it's no surprise that it sometimes "just works" for some people, and
> sometimes just can't be made to do what you really wanted it to do.
> 
> ATA confuses me. It irks me no end that ATA has become mainstream, while
> SCSI gets no respect.

SCSI gets a lot of respect.   It also costs a lot more $ than IDE/ATA so
it is harder to get the home user to justify the extra expense.

> 
> To say what I meant to say, I removed the _second_ controller card (not
> slave controller or whatever it was I said) and have both drives on the
> mobo's controller's primary channel, with the CD drive all by itself on
> the secondary channel (pretending to the BIOS that it's SCSI no less).
> Grub is on the drive on the "master" connector (closest to the
> controller on the cable, strapped CS), along with FC3, and two BSDs. The
> drive connected to the slave controller (which is actually there to be a
> spare because I don't trust ATA drives) has another BSD and sometimes
> other Linux on it.
> 
> I had planned to spread swap across the two drives, in BIOS-level
> partitions shared by all OSses, and I will probably do so when I put the
> other controller back in. But for now, keeping all of my partitions for
> each OS on the drive that OS resides on allows it to "just" (ahem) work.
> (Yeah, right. It doesn't do what I really most wanted it to do, didn't
> get some important jobs done, but it's useable, just. Hey, Netbeans runs
> fine on it. I'll probably end up plugging a TV card in it and using it
> instead of the TVs that keep dying on us.)
> 
> Sigh. I've forgotten why I bothered posting that. (And I don't think I
> want to remember.) Sorry for the noise.
> 
> 


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