Disk maps on unix disks (a standard???)
Dennis L. Mumaugh
dlm at cuuxb.ATT.COM
Tue Apr 26 08:52:54 AEST 1988
In article <355 at tandem.UUCP narayan at tandem.UUCP (Narayan Mohanram) writes:
In most unix systems, when one makes a file system via an
FSCK, they have to dig up the manual for the disk type to
see how the disc driver has laid out the disk (the various
partions sizes, and starting point). Has any-one come up
with a standard for putting these partition map info on
the front a disk on a super-super block so to speak. Then
one can mount a disk pack on any unix system, and read it.
The drivers/unix can get the info from the front of the
disk.
On UNIX System V for the ATT 3B2/5/15/4000 the second sector on
the disk is the VOLUME TABLE OF CONTENTS (vtoc). It describes
the disk's partitioning. The first 100 sectors of any disk (hard
or floppy) are the boot sectors and excluded from the unix file
system. One "partition" ususually 6 included the whole disk but
of course one couldn't mount it as the disk didn't look like a
real filesystem.
There were some pre-defined vtocs for "default" or naive users.
--
=Dennis L. Mumaugh
Lisle, IL ...!{ihnp4,cbosgd,lll-crg}!cuuxb!dlm
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