[Beowulf] A press release

[Tim Cutts]

On 4 Jul 2008, at 8:23 am, Geoff Galitz wrote:

>
>
> Just a nit:
>
>
>
> Most RPM based distros allow in-place upgrades between minor point  
> releases
> using "yum update" or "yum upgrade" (they follow different rules on  
> how to
> resolve obsolete packages).  However, moving between major releases  
> is still
> recommended via a CD or other non-in-place media, though there are  
> people
> that have done it in-place you seriously risk inflicting harm to  
> your system
> in this manner.
>

But that's the whole point - why is that the case?  It shouldn't be.

If upgrading packages wrecks the system, then the package installation  
scripts are broken.  They should spot the upgrade in progress and take  
appropriate action, depending on the previously installed version.   
This can be quite a detailed process for Debian packages, which is  
probably why they have fewer problems than Red Hat in this regard.   
See http://www.debian.org/doc/debian-policy/ch-maintainerscripts.html#s-mscriptsinstact 
  if you're interested in how it works for Debian packages.

OB clustering:  For cluster nodes, we never do dist-upgrades, though.   
A reinstall from scratch is actually faster, so in the context of this  
list, the ability to upgrade in place isn't terribly important.  A FAI  
install of a basic debian 4.0 image on a cluster node takes about two  
minutes, so there's not much point in going through the upgrade  
process, which takes considerably longer.

Tim


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