Mail Archives: opendos/2001/11/28/01:05:03
The MBR stores the main partition table - no logical drives are defined
here.
The first cylinder of the extended partition contains another partition
table. The logical drive cannot start at the beginning of the extended
partition - there must be one track for the partition table.
This partition table can only hold 2 entries - the logical drive and another
"extended" partition. This new "extended" partition also has a partition
table in the first track (thus daisy chaining).
The effect is that each logical drive is wrapped in its own "extended"
partition. However in essence the Extended partition is continuous as there
can be no Primary partitions in this area.
I'm not sure if this is the sort of information you were after.
Regards
Joydeep Mitra
>From: "da Silva, Joe" <Joe DOT daSilva AT emailmetering DOT com>
>Reply-To: opendos AT delorie DOT com
>To: "'opendos AT delorie DOT com'" <opendos AT delorie DOT com>
>Subject: RE: Extended partitions (was: FDISK)
>Date: Tue, 27 Nov 2001 12:29:16 +1100
>
>I wonder is someone could perhaps clarify something that is
>puzzling me about logical volumes in extended partitions :
>
>As described earlier by Bob, these are a daisy chain of
>"extended partition boot sectors". Does this mean that
>each logical volume has an extended partition table sector,
>akin to the MBR? If so, where are these sectors located on
>the disk (eg. sector 2, etc. of the first track, perhaps)? Or
>does this mean that logical volumes have their "partition
>table" parameters stored in the "DOS boot sector" instead?
>
>Joe.
>
> > -----Original Message-----
> > From: Robert W Moss [SMTP:domanspc AT juno DOT com]
> > Sent: Friday, November 03, 2000 12:20 AM
> > To: opendos AT delorie DOT com
> > Subject: RE: FDISK
> >
> ------ snip ------
>
> > If a disk is set up with two or more partitions, FDISK shows only two
> > total
> > DOS partitions: the primary partition and the extended partition. The
> > extended partition is then divided into logical DOS volumes, which are
> > partitions themselves . FDISK gives a false impression of how the
> > partitioning is done. FDISK reports that a disk divided as C, D, E, and
> > F
> > is set up as two partitions , with a primary partition having a volume
> > designator C and a single extended partition containing logical DOS
> > volumes D, E, and F. But in the real structure of the disk , each
> > logical
> > DOS volume is a separate partition with an extended partition boot
> > sector describing it. Each drive volume constitutes a separate
>partition
> >
> > on the disk, and the partitions point to one another in a daisy-chain
> > arrangement.
> >
> ------ snip ------
>
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
- Raw text -