reboot during upgrade

[Giorgos Keramidas]

On Fri, 29 Aug 2008 16:23:37 -0700, Chuck Swiger <cswiger at mac.com> wrote:
>> what consequences would appear if i'll reboot the machine once during
>> the upgrade?
>
> If you don't reboot in order to be using the new kernel before
> installing the new userland, you'll install critical things like sh
> and make which might not run using the old kernel.  You might find
> that the installworld part fails in the middle, and the system is left
> in an unusable state which is very hard to recover from.

Not to mention that if installworld suceeds but the new kernel panics at
every boot, you may end up with a userland that uses 'new' stuff to work
but with an unbootable kernel.  Rolling back to kernel.old may work (and
it usually does), but it's not a safe bet all the time.