Subject: Re: disklabel number of partition ?
To: Richard PLOIX <>
From: Manuel Bouyer <>
List: tech-net
Date: 06/29/2000 22:00:51
On Thu, Jun 29, 2000 at 10:35:58AM +0200, Richard PLOIX wrote:
> hello,
> I need more than 8 partition on a disk.
> is this is possible ?

Yes, but a bit tricky, especially if you have more than one disk.
- in i386/sys/disklabel.h, change MAXPARTITIONS from 8 to e.g. 16
- build a new kernel and install it, but don't reboot.
- edit /dev/MAKEDEV and change all disks entries to make 16 nodes instead of 8
  (which means wd1a will become minor number 16 instead of 8). run
  'MAKEDEV all' in /dev
- now reboot with the new kernel. It should be able to mount your disks
- run a 'make build'
- now you can make and use partitions i->p

The problem is that for all but the first disk, minor number changes:
wd0a or sd0a is always minor number 0, but wd1a or sd1a will have minor 
number 16 instead of 8. This is why you have to rebuild the device nodes
before rebooting the new kernel (otherwise you'll have to use wd2a for wd1a).
If you reboot an old kernel after rebuilding the device nodes, you'll have
problems also (if you understood how it works you'll know to use wd0i for
wd1a :).
Of course if you have only wd0 and/or sd0, a lot of problems go away :)

Manuel Bouyer <>