[pca] Cluster, zones, noreboot.

[David Stark]

Hi List.

A bit off-topic, but PCA's involved, so I'm going to push my luck.

We've got a number of Sun Cluster installs using (lots of) failover 
zones and with no LiveUpgrade alt. boot space set up, which we need to 
patch. If we were to patch the clusters node-by-node (including the 
kernel patches that don't like zones being booted when they're applied), 
the zones would fail over between the nodes and never get patched 
themselves, and since kernel (and some other?) patches can't be applied 
from inside zones we would end up in a situation where the zones' patch 
databases are out of sync with the Global zone. I know from very bitter 
experience that this is a Bad Thing, so to avoid that we're currently 
bringing the clusters down to patch them. This obviously isn't optimal - 
people expecting 100% uptime from the clusters are naturally a bit 
annoyed at having their applications down for several hours while we 
unleash the mighty PCA.

So, to minimise downtime I'd like to apply the noreboot patches, say, 
the night before, and have a more minimal patch run with the clusters 
down. This brings me to the question:

Has anyone ever had any problems with noreboot patches applied to live 
systems? Any weirdness at all? I've patched plenty of test machines in 
multi-user mode, but never busy production boxes - these are fairly 
large Oracle and SAP environments for the most part.

Anyone with experience patching Sun Cluster care to share any top tips?

Cheers!

Dave