GEOM and moving to CURRENT from 7.1

[Robert Watson]

On Sun, 11 Jan 2009, George Neville-Neil wrote:

> Beware if you are upgrading from a 7.1 system to CURRENT that you may need 
> to have the kernel options GEOM_MBR and GEOM_BSD in your kernel.  I spent a 
> couple of hours dealing with this on my Thinkpad X60 today which had, what I 
> thought, was a pretty simple setup of 1 slice for BSD, and a simple layout 
> of /, swap and /usr.  When I tried to boot the new kernel I got to the mount 
> error prompt and could not mount ad4p1 or anything like it. Adding the 
> GEOM_MBR and GEOM_BSD options back into the kernel fixed things. Happily I 
> was able to boot 7.1 still and fix this.

Just to follow up on George's post -- he and I spent a bit of time last night 
trying to reconcile the fact that he and a few other people found themselves 
without bootable kernels, while many people don't.  For example, my VMWare VMs 
all seem to boot without a problem, perhaps due to having particularly boring 
and vanilla fdisk/bsd labeling.  Certainly, it seems that the message in the 
short term when upgrading to an 8.x kernel, or sliding forward, is that some 
caution is required, so make sure you have a backup kernel in case things 
don't work out.  (This is always true in -CURRENT, of course...)

Robert N M Watson
Computer Laboratory
University of Cambridge