[rescue] rescuing an ailing U10...

Jonathan C. Patschke jp at celestrion.net
Mon Oct 1 19:44:32 CDT 2007

On Mon, 1 Oct 2007, James Hartley wrote:

> The Nevada build I have comprises six CD's.  Sun ensures that
> everything necessary is always on the first disc?


> Do you know where this magic number is written?  Somewhere within the
> MBR?

Most Unixes don't actually use an MBR like Windows and Linux do.  They
use a disklabel[0], which is similar in concept, but very different in

The missing magic number is the number at the start of the disk that
indicates presence of a Solaris disklabel (also called a VTOC).  MBR has
a magic number of its own: 0xAA55 in the last two octets of the first
block of the disk.

Some OSes (FreeBSD and OpenBSD and NetBSD and presumably Solaris on x86
hardware) can use either MBR or disklabels, but usually nest a disklabel
inside of whichever MBR partition they own, so you get a confusing
two-level hierarchy of partitions and slices.

[0] And then you have the Unixes with native LVMs like AIX, HP-UX, and
     Tru64, which use something altogether different.
Jonathan Patschke     )  "So far, 99% of illegal activity has been caused
Elgin, TX            (    by criminals."
USA                   )                                    --David Willis

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