[1376] in netbsd-help mailing list archive
Re: mounting linux partition under netbsd
daemon@ATHENA.MIT.EDU (Nathan J. Williams)
Tue Dec 8 01:40:52 1998
To: Richard S Tibbetts <tibbetts@MIT.EDU>
Cc: netbsd-help@MIT.EDU
From: "Nathan J. Williams" <nathanw@MIT.EDU>
In-Reply-To: Your message of "Tue, 08 Dec 1998 00:26:03 EST."
<199812080526.AAA00954@ten-cent-crack-whore.mit.edu>
Date: Tue, 08 Dec 1998 01:40:43 EST
> I a hoping to mount linux (redhat 5.1) formatted partitions under NetBSD
> Athena. I have been told that this involves messing with the disklabel
> under NetBSD.
> linux fdisk says my disk looks like this (retyped, not copied)
>
> Partition begin start end blocks type comment
> hda1 1 1 261 2096451 a5 NetBSD
> hda2 262 262 524 2112547+ 5 dos extended
>
> hda5 262 262 338 618471 83 /
> hda6 339 339 355 136521 82 swap
> hda7 356 356 524 1357461 83 /usr
I'm guessing you're interested in what the Linux side thinks
of as /usr, not /.
> Currently my disklabel looks like this:
[deleted]
> 6 partitions:
> # size offset fstype [fsize bsize cpg]
> a: 204800 63 4.2BSD 1024 8192 16 # (Cyl. 0*- 203*)
> b: 131072 204863 swap # (Cyl. 203*- 333*)
> c: 4192902 63 unused 0 0 # (Cyl. 0*- 4159*)
> d: 8421840 0 unused 0 0 # (Cyl. 0 - 8354)
> e: 131072 335935 4.2BSD 1024 8192 16 # (Cyl. 333*- 463*)
> f: 3725312 467007 4.2BSD 1024 8192 16 # (Cyl. 463*- 4159*)
> so, my problem is, what do i do about the extended partion?
> generally, i dont know where to begin. if someone could
> point me to a faq, that would be great.
There's a NetBSD/i386 FAQ at
http://www.netbsd.org/Ports/i386/faq.html, which discusses adding a
MS-DOS partition. The details are different, but the basic concept is
the same. You need to add to the NetBSD disklabel an entry with the
size and offset of the Linux partition in question. The size and
offset need to be in units of sectors (512 bytes), but the Linux side
is reporting in cylinder numbers using some translation schem (since
it is using 524 as the largest cylinder, while NetBSD is using 8355 as
the largest cylinder. It's not totally clear what the translation
scheme is from the linux information in your message.
Making some wild assumptions about how the numbers add up
(assumming that the start of the Linux /usr partition is the start of
BSD partition f + size of f + size of Linux / + size of Linux swap),
the line to add would look like:
g: 1357461 4947311 ext2fs
and you'll have to change the number of partitions from 6 to 7.
In short, you need to enough poking around on the Linux side to
figure out exactly where, in sectors, the partition you care about
lies, and then put those numbers into an entry in the disklabel with
disklabel -e. Then you can add a line to /etc/fstab to mount it;
something like:
/dev/wd0g /linux ext2fs rw
should do the trick.
- Nathan
