[pca] Single-User revisited

[Ray Van Dolson]

On Thu, Sep 11, 2008 at 06:44:26AM -0700, Fred Chagnon wrote:
> I know it's an age-old question. To patch in single-user, or not. 
> 
> I'm concerned mostly about the patches that require a reconfigure
> reboot. For example sparc kernel patches 120011-14 or 127127-11. Has
> anyone had any problems applying these patches in multi-user mode on a
> running system?

I do this on non-production systems that admittedly aren't too busy.
Haven't yet encountered an issue.  However, I wouldn't do this on
anything production. :)

> I'm asking because I would like to implement the use of a pca proxy, but
> I figure in order to download a patch from the proxy, I can't be running
> in single-user mode -- and as much as possible I would like the process
> to be streamlined such that applying kernel patches uses pca the same as
> any other trivial patch. 
> 
> Thanks for any insight. 

I have also applied patches via pca proxy in run-level 1.  The other
thing you could do is pre-download the patches with pca before going to
run level S and then use pca again to apply them (but they'd already be
downloaded).

Something like the following:

1. Use pca via proxy to apply all safe patches which do not require a
   reboot.
2. Use pca via proxy to download all the othe patches you want to apply
   but do not apply them.
3. Go to single user mode
4. Use pca to apply the patches you downloaded from your proxy above.

Ray

> --
> Fred Chagnon
> fchagnon at gmail.com