Re: Disk label problem?

[Ted Spradley <tsprad%talent-free-studios.com@localhost>]

On Wed, 15 Jun 2022 05:12:37 -0000 (UTC)
mlelstv%serpens.de@localhost (Michael van Elst) wrote:

> tsprad%talent-free-studios.com@localhost (Ted Spradley) writes:
> 
> >As long as it's the only disk attached this boots up and works fine:
> >But if there is any other drive attached, that other drive gets mounted as root (apparently).
> 
> What is on that other drive ?

The other drive was a NetBSD-5.1 raid pair, one of which was apparently damaged.

> Here is a rough description of the default boot process:
> 
> 1. BIOS reads the MBR, usually a BIOS setting that identifies from which drive that is read.
> 2. The secondary bootloaders are read from the same drive.
> 3. The kernel is usually read from the same drive.
> 4. The kernel tries to guess what the root partition is, usually by identifying the partition bootblock.
> 
> So "that other drive gets mounted as root" may mean that BIOS boots
> from it, or that it gets misidentified by the kernel. The latter
> can happen if it is (to some degree) a copy of the first drive.

My best guess now is that EUFI loaded the 9.2 kernel from the /boot (msdos) partition, but the borked GPT label prevented it from recognizing the root filesystem, so it chose the 5.1 root instead, given the choice.

In any case, the problem is resolved now because I mistakenly typed "of=/dev/rwd0a" when I meant rwd1a. I re-installed 9.2 and now I have a good GPT label.

-- 
Ted Spradley <tsprad%talent-free-studios.com@localhost>