Re: reboot during upgrade

On Fri, Aug 29, 2008 at 10:15:18PM +0000, Matkhamtkha Brekher wrote:
> sorry guys for the oftopic but can someone tell me why this guide from
> /use/src/Makefile:
> 
> #  1.  `cd /usr/src'       (or to the directory containing your source tree).
> #  2.  `make buildworld'
> #  3.  `make buildkernel KERNCONF=YOUR_KERNEL_HERE'     (default is GENERIC).
> #  4.  `make installkernel KERNCONF=YOUR_KERNEL_HERE'   (default is GENERIC).
> #       [steps 3. & 4. can be combined by using the "kernel" target]
> #  5.  `reboot'        (in single user mode: boot -s from the loader prompt).
> #  6.  `mergemaster -p'
> #  7.  `make installworld'
> #  8.  `make delete-old'
> #  9.  `mergemaster'
> # 10.  `reboot'
> # 11.  `make delete-old-libs' (in case no 3rd party program uses them anymore)
> 
> 
> tells me to reboot the machine twice?
> after 4th step and then after 9.
> 
> what's the point? is it dangerous to do it only once after 9 step and
> not after 4?
>
Step 4 installs new kernel preserving the old one as kernel.old.
It may happen that the new kernel does not work properly (especially
if you are on CURRENT). Booting the new kernel at this moment helps
diagnose these situations and reverting back to the old kernel fixes the
problem.

> what consequences would appear if i'll reboot the machine once during
> the upgrade?
>
If you install both kernel and world and notice that the new kernel does
not work later (after step 9), you cannot revert to the old userland.
And sometimes new world does not work with old kernel.

Apart from this, nobody and nothing forbids you to cut the corners.
But then you should know what you are doing :->

Just my 0.02$,
Alexey.