[LON-CAPA-admin] system will not boot

[Guy Albertelli II]

Hi Rob,

> Without making any changes to our system, it now locks up starting
> httpd and gives the warning:
> module perl_mod already loaded, skipping.
> We've seen this error in the past, but it kept on going and
> everything went fine, but now the machine hangs up at this spot.
> Has anyone seen this before?

My guess is that the network setup is wrong in some way.

The quick fix is to boot it with no network cables attached. 

At webserver startup (in 2.3 and earlier) the webserver does a
hostname lookup on everything in the hosts.tab file.

For a system that has a malconfigured network, this can take a long
time to finish (as the failure time for a hostname lookup can be 
over a minute per hostname.)

As the number of hosts in the hosts.tab file is large (over 100) this
means it can take over 100 minutes to startup when there is a bad
network setup in which every lookup slowly fails.

By unplugging the network things will fail more quickly and you can
then have the machine up quickly. Then plug the network cable back in
and try to debug the network setup.

You can see (once the machine is up) if the hostname lookup is failing
by restarting the webserver on an up machine and watching the
lonnet.log file.

Alternatively just waiting should also work to bring the machine up,
but you'll still need to fix the network setup to have a functional
machine.

-- 
guy at albertelli.com   0-7-0-9-27,137