Re: Rép. : thoughts on synchronizing config between failover partners

John Abbott abbottj at
Thu Oct 19 20:35:46 UTC 2006

I use sum on another system redirect to an /var/tmp/.sum file. Then each cro rin it simply compares the sum of /var/tmp/.sum with /etc/dhcpd.conf, if they differ then its changed and copy to other server + restart

That also seems to work.


>>> "Serveur-Faucon Surveillance" <SrvFaucon at> 10/20/06 4:00 AM >>>

I was thinking about doing it semi-manual, or semi-automatic.

Since only admins can change the dhcpd.conf file they would have to execute the bash script.

The bash script would do something like...


test the local dhcpd.conf file, if not okay, then error
test the local leases file, if not okay, then error
reload local dhcpd
copy the dhcpd.conf to the other server
reload the other server dhcpd


It could be the same if it would be in the cron.

OR in the future, that could be in cfengine. With cfengine, everything can be updated on changes.

Alexandre Racine - Gardien Virtuel - Sécurité Informatique
Montréal, Québec, Canada

>>> abennett at 2006-10-18 11:05:19 >>>

I'm curious what other people do about syncing your config files between 
failover peers. 

When I've got this all implemented, I'm planning to hand it to a network 
engineer and I'd like to give him a more elegant way to keep the config 
files in sync then 'make the same edits to the file on each host' 
method.  I was thinking of a solution with an nfs share and a cron job 
running on the other host, like..

host1: shares /var/dhcpd_config to host2.

edit /etc/dhcpd.master (included by /etc/dhcpd.conf) on host1.  Copy it 
to /var/dhcpd_config and restart dhcpd.

cron job on host2 sees change to /var/dhcpd_config/dhcpd.master, copies 
it to /etc, restarts dhcpd.

Fairly simple.  Of course I'd do stuff like preserve the old version, 
etc, and use iptables to make sure only host2 can access the share.  How 
do you handle this?



Aaron Bennett
Sr. Unix Systems Administrator
Clark University ITS
abennett at     |     508.781.7315

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