Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 07 Apr 2001 00:27:26 -0400
From:      The Babbler <bts@babbleon.org>
To:        Rasputin <rara.rasputin@virgin.net>
Cc:        stable@freebsd.org
Subject:   Re: Disklabel 101?
Message-ID:  <3ACE972D.A13CF44C@babbleon.org>
References:  <20010405111707.A35325@dogma.freebsd-uk.eu.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Rasputin wrote:
> 
> Is there a decent walkthrough anywhere on the Net for using
> disklabel, fdisk , etc - along with an explanation of what a,c etc all
> mean?
> 
> man disklabel etc all assume you know what those letters mean.
> I know c is the whole partition, but that's it.

c = entire disk
a = root
b = swap
d = ???   I don't know; it's never used
e+ = other partitions.

BTW, does anybody know *why* BSD uses such a bizarre scheme?

> 
> I need to know because:
> 
> <PHYSICAL><-----EXTENDED-----><------PHYSICAL------------>
> 
>  ad0s1    ad0s5    ad0s6      ad0s3
> <-winXX--><-msdos-><Slackware><-------BSD---------------->
> |  2Gb    |  1.5Gb | 2Gb      | / | swap | /usr  | /var   |
>                       ^
>                       |
> I have an old Slackware partition
> that has FUBARed itself so throuoghly that it can't even be mounted.

This isn't really disklabel at all; it's the low-level format, which is
why I can help.

> 
> (Actually there were about 3 partitions in there, but they're lost now)
> It's in the second logical partition in an extended DOS partition on
> my second physical partition (dev/ad0s6 in FreeBSD)
> There's a Gb of data in ad0s5 (which is fine).

FreeBSD doesn't know from extended partitions from what I can see.  Does
your FreeBSD actually see od0s5/ad0s6?  'Cause mine never seemed to
found; I used PartitionMagic to convert my DOS partition from logical to
primary largely to deal with this.

Was I missing a big clue?

Try typing "fdisk /dev/ad0" to get an idea of how FreeBSD really sees
your disk.

Anyway, as far as *I* am aware what you've really got is:

ad0s1 - first partition = winXx
ad0s2 - second partiion = extended
ad0s3 = third partition = BSD

The disklabel program is concerned only with dividing up ad0s3.

You can make a file system on ad0s2 and it certianly ought not overlap
anything, but run "fdisk" to be sure things are really confused.

If you can access ad0s5/ad0s6, please let me know.  It would be news to
me!

(And what release are you running, BTW?)


> BSD dumps ad0s6 altogether when it boots; and fdisk from a
> boot CD says something along the lines of:
> "Second slice extended past end of disk" or similar
>         (box is offline today, so I can't check right now)
> This concerns me; if I try to fdisk/newfs ad0s2 (assuming I
> could see it), I risk losing ad0s3, which is the only bit of the disk
> I really want to keep.
> 
> I assume/hope that if I blow away the extended partition
> entirely, I can just recreate it.
> But I don't really know what it's called?
> Is it ad0s2?
> And won't I need to let BSD know where / has moved to?
> 
> What I'd really like is some advice from anyone who knows this stuff.
> But I'm surprised the Handbook doesn't go into a lot of detail on this,
> since dual-boot systems are fairly common amongst cheapskates like me.
> 
> If I can free up that 2Gb, maybe I'll have space for the docproj port... :)
> --
> Rasputin
> Jack of All Trades :: Master of Nuns
> 
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-stable" in the body of the message

-- 
"Brian, the man from babble-on"              bts@babbleon.org
Brian T. Schellenberger                      http://www.babbleon.org
Support http://www.eff.org.                  Support decss defendents.
Support http://www.programming-freedom.org.  Boycott amazon.com.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3ACE972D.A13CF44C>