Subject: Re: Another changer, another changer problem
To: Roger Brooks <R.S.Brooks@liverpool.ac.uk>
From: David Maxwell <david@fundy.ca>
List: current-users
Date: 10/03/1998 16:04:52
On Sat, Oct 03, 1998 at 02:40:30AM +0100, Roger Brooks wrote:
> On Fri, 2 Oct 1998, David Maxwell wrote:
> 
> >
> >My answer to the second question is this -> you put two drives on SCSI ID 1,
> >you shot yourself in the foot. Have a nice day. As for the groping, yes it's
> >a bit ugly, but it's only once, at mount time.
> 
> Yes, but you can (and should) change the SCSI ID *before* you connect the
> disk to your system.  But what if you want to attach a disk with a label
> which collides with one on an existing disk.

Boot with -s, and use whatever the partition naming utility is called to
rename one of the disks. Better still, don't name two partitions the
same in the first place, that's what I meant to imply with the dm_root.
Think of ws_root (webserver root) ms_root (mailserver root) or whatever
use of the namespace appeals to you.

Alternately, the mount '-l' could detect duplicate names and prompt at
boot time.

> Suppose you want to connect
> the system disk of a non-working machine to another system so you can examine
> it and work out what's wrong, and both are labelled "NetBSD_1.3.2".
> You can't change the label until you've connected it, and you can't connect
> it until you've changed the label.  You're stuffed!

I've never looked to see if the boot process actually obeys fstab, or if
it simply uses the disk the kernel was loaded from. I assume the latter,
since it can't read the fstab until the / partition is mounted. I don't think
the mount '-l' semantics I'm hypothesising about really apply to the root 
partition.

-- 
David Maxwell, david@vex.net|david@maxwell.net --> Mastery of UNIX, like
mastery of language, offers real freedom. The price of freedom is always dear,
but there's no substitute. Personally, I'd rather pay for my freedom than live
in a bitmapped, pop-up-happy dungeon like NT. - Thomas Scoville