Subject: Re: A FreeBSD problem (off topic ?)
To: Steinar Hamre <>
From: Rakhesh Sasidharan <>
List: netbsd-users
Date: 08/16/2000 18:37:58
On 16 Aug 2000, Steinar Hamre wrote:

> FreeBSD disklabel partitions is offset from the start of the
> "PC"-partition (primary or logical doen't matter), NetBSD disklabel
> partitions covers the entire adress space of the disk.
> In FreeBSD you access other "PC"-partitions via the "slice"-devices
> (/dev/ad0s1 and so on).

Actually, the problem is slightly more technical.  I know how FreeBSD
handles disklabels, but what I (more precisely) want to know is how to
construct one.  That is, when I installed NetBSD after installing FreeBSD,
FreeBSD somehow automatically recognized the partitions in the NetBSD
slice and made the entries etc for it.  I wan't a similar thing for my
extended partitions.

I figured out that if I were to make an ASCII file filled with the
partition info (calculated based on the start and end points and the known
sizes of each partitions), then I can used 'disklabel -e -R filename wd0'
to make FreeBSD acknowledge that partition.  But I think (and please
correct me if I am wrong) that this in someway makes it write the info to
the hard-disk itself.  Coz, I had OpenBSD long ago, and FreeBSD didn't
automatically figure the OpenBSD slice, and then I had to use this
technique to get things to work.  But then, that spoilt OpenBSD's view of
things (as you said earlier, disklabels are treated different in FreeBSD
and Net/OpenBSD), and I had to edit things once more there to make things

Is this the right way to do things ?  Or is there someother way in which I
could have got FreeBSD to recognize my OpenBSD side ?  And how should I go
abt getting it to recognize my Linux logical drives ?  If I just type
'disklabel -e wd0s3' (where wd0s3 is the Linux part), it gives me some
error.  Then I tried 'disklabel -e -r wd0s3' and it said the slice is
unlabelled.  The only thing I can think of, is the '-R' option.  But I
hope it won't distort Linux's view of things.  Any advice please ?

> > And while I am on it, why is it that I can have only 8 partitions (a-h) ?
> > Is there any way to increase it.  `a' is root, `b' is swap, `c,'`d' are
> > reserved, and `e,'`f' have /usr and /var on them -- leaving me with just
> > `g' and `h.'  Anyways to increase the number ?
> Most NetBSD ports have a upper limit of 8 partitions. OpenBSD/i386
> have 16 partitions. I think we should go for this or a even higher
> number of partitions (32? 256?). Increasing the number of partitions
> will probably result in a incompatible disklabel, but in my opinion,
> disklabels will have to be redone sooner or later anyway, as most
> information kept in the disklabel is way out of date.
What do u mean by incompatible disklabels ?  Between the different BSD's,
or something else ?