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From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.unix.wizards
Subject: Re: Trashed partition table on a Trimarchi Datastaion 600 disk
Keywords: partition table DECStation 3100 Trimarchi
Message-ID: <21145@mimsy.umd.edu>
Date: 6 Dec 89 23:10:51 GMT
References: <1483@utkcs2.cs.utk.edu> <1485@utkcs2.cs.utk.edu>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 18

In article <1485@utkcs2.cs.utk.edu> battle@alphard.cs.utk.edu (David Battle)
writes:
>The problem appears to have been that the "b" partition started at the very
>beginning of the disk (the "a" partition was 0 length) but the partition table
>is normally stored at the beginning of the "a" partition (isn't it?).

Ultrix (and only Ultrix) stores the partition table in the super-block
area.  Of course, this assumes there *is* a super-block area at the
beginning of the disk.

4BSD (sufficiently recent versions) and SunOS both put the label in block
zero, and put the partition table in the label.  4BSD (but not SunOS, or
older versions thereof, at least) also allows swapping on the region
containing the label (it avoids stepping on sector 0, whether the disk is
labelled or not).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris