Re: Labelling/Partitioning disks - once more with feeling!

Jim Paradis (paradis@amt.tay1.dec.com)
Fri, 27 Oct 1995 02:45:47 -0500 (EDT)

> MILO can see the disk and read its contents fine. A kernel started
> on their boots fine *until* its gets to the mounting of the root
> filesystem stage. Then I get this set of messages:-
> [MS-DOS FS Rel. 12, FAT 0, check=n, conv=b, uid=0, gid=0,
> umask=022, bmap]
> [me=0x0, cs=0, #f=0, fr=0, fl=0, ds=0, de=0, data=0, se=0, ts=0,
> ls=0]
> Transaction block size=512
> Kernel Panic: VFS: Unable to mount root on 03:41

*sigh* you need a newer version of minlabel (like, the one that I'm
putting into BLADE 0.3).

The problem I think you're seeing is due to the fact that the disk
you're using *used* to have an fdisk-style partition table on it.
Fdisk puts a "magic number" (0x55aa) at the end of sector zero to indicate
that there's a valid fdisk-style partition table there. Minlabel
does not touch that area of sector zero because that's not near the
disklabel itself. The net result is that if you minlabel a disk that
had a previous fdisk-style partition table on it, Linux sees the 55aa,
assumes it's got an fdisk-style partition table (which it doesn't),
parses garbage, and goes into the weeds.

For now, if you can attach that disk to another system, zap out the
last two bytes of the first 512-byte sector and see if things get
any better...

-- 
Jim Paradis (paradis@amt.tay1.dec.com)        "It's not procrastination, 
Digital Equipment Corporation		       it's my new Just-In-Time 
(508)952-4047				       Workload Management System!"