upgrading

[Matthew Seaman]

On Sun, Sep 21, 2003 at 01:13:11PM +0200, Alban Hertroys wrote:
> On 21 Sep, Matthew Seaman hit a keyboard in the following places:
> >     # shutdown -r now
> 
> Hmm, I usually prefer to do  just: #shutdown now
> so that I end up in single user mode immedately. I usually check 'ps' to see
> whether no daemons are running (fleeing?) that should have died.
> This method has the effect that you're still running the same kernel,
> but I'm now unsure whether that's a good or a bad thing.
> 
> If you reboot (with '-r'), you are booting a system where the kernel is
> upgraded, but the rest of the system isn't. That could cause startup
> scripts to fail and the like.

Uh... That's the whole point.  You've just installed a new kernel and
you need to reboot using that kernel to make sure it works.  If the
new kernel fails to boot, it's fairly simple at this stage to back out
to the previous kernel, boot back up to multiuser and try again.  

Doing an installworld before you've verified that the kernel is
properly bootable could get you stuck up a gum tree -- there's no easy
way to undo a 'make installworld' and you'ld probably be forced to
recover the system from backup.  However, you don't want the system to
boot all the way up to multiuser immediately as that would give you a
new kernel and an old world.  Hence the reboot into single user step.
 
> OTOH, if you don't, are you using the installed install tools or the
> upgraded ones (which may require the new kernel) when running
> installworld?

make installworld is very carefully written to be able to succeed even
if there is a fairly large jump in versions between what's installed
and what's due to be installed.  Even so, sometimes you need to take
extraordinary steps: these will be detailed in UPDATING, but usually
come down to running 'mergemaster -p' before you do your 'make
buildworld'.
 
> I'm getting a bit confused here...
> 
> > (Various output will scroll past.  When prompted for what shell to
> > run, just hit return)
> > 
> >     # fsck -p
> >     # swapon -a
> >     # mount -a
> 
> Careful there, you don't want to mount NFS mounts and the like. I
> usually do (depends on your partitioning):
> 
> 	mount -u /
> 	mount /tmp
> 	mount /var
> 	mount /usr
> 
> I usually leave out /home and other mount points that aren't needed by
> installworld, so that they can't get corrupted if something gets
> screwed up (likely by me).

You can't pick up any NFS mounts in single user -- the network hasn't
been configured yet.  But, yes, some people will want to be extra
careful and run variants on the basic process.  You might find a
command like:

    # mount -a -t ufs,mfs

handier, although it will probably still pick up your /home.
 
> Looking at the mount man page, you could also create an alternate
> "minimal" fstab file, and do mount -a -F <your minimal fstab here>.
> I think I'll have a (f)stab at that... ;)

That's certainly a possibility, but I think it would be overkill for
most people.

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK
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