== Why I'm not really interested in Solaris's Live Upgrade stuff

Solaris Live Upgrade is one of those things that I would like to love,
but I can't seem to get interesting in, and here's why.

First, as I've [[written before ../sysadmin/PatchingAppliancesSystems]],
we don't patch our [[Solaris machines ZFSFileserverSetup]]. They're only
accessible internally and they're effectively black-box appliances;
there's very little enthusiasm here for patching a working appliance.

When we do patch our Solaris machines, we never need to roll back
patches because we test them first in a test environment. We have
no choice about this; we cannot possibly deploy an untested patch
into a production environment, fast reversion or no. (Sadly our
experience with Solaris patches is that we definitely do have to
test them.)

(Also, we don't patch machines in single-user mode regardless of
what the Solaris patches claim to require; in fact we just apply
all of our patches through [[pca
http://www.par.univie.ac.at/solaris/pca/]].)

Solaris LU couldn't save us from a server downtime either. Even with LU
you need to reboot the machine in order to activate your new patches,
and rebooting a fileserver always requires a formal downtime (which is
one reason that we don't have very much of an urge to patch fileservers
unless it is really important).

(I've written before about how we do [[fast OS upgrades
../sysadmin/FastOSUpgrades]]. LU might make those simpler, but it does
so at the cost of making an upgraded machine subtly different from a
machine that we (re)install from scratch, unless we make (re)installs
take even longer than they already do.)

I admit that I would feel more interested in just exploring
Solaris LU if it hadn't [[already hung on me once or twice
SolarisToolScalability]]. I have a very low tolerance for bad behavior
from tools like Live Upgrade; any bugs are generally enough to make me
give up on the tool entirely (for reasons that don't fit in this entry).