Message-ID: <01FD6EC775C6D4119CDF0090273F74A455A85F@emwatent02.meters.com.au>
From: "da Silva, Joe" <Joe DOT daSilva AT emailmetering DOT com>
To: "'opendos AT delorie DOT com'" <opendos AT delorie DOT com>
Subject: RE: Extended partitions (was: FDISK)
Date: Thu, 29 Nov 2001 10:03:06 +1100
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Reply-To: opendos AT delorie DOT com

Thanks!

One further question ... Can extended partition chains be a mixture
of partition types, from different OSes? For example, can DR-DOS
(say 6.0) and Linux extended partitions be linked in a chain, or will
this confuse DR-DOS (or similar DOSes)?

Joe.

> -----Original Message-----
> From:	Joydeep Mitra [SMTP:jolly_joydeep AT hotmail DOT com]
> Sent:	Wednesday, November 28, 2001 5:01 PM
> To:	opendos AT delorie DOT com
> Subject:	RE: Extended partitions (was: FDISK)
> 
> 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 ------
> >
> 
> 
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