[DRBD-user] meta-disk

[Chip Burke]

Csync is exactly what I am looking for. As it stands no, we have /var, /usr
and /home on a separately mounted RAID array. I can use DRBD to keep that up
to date and then Csync for the config files. In addition, heartbeat takes
care of the failover... Off to the subterranean laboratory!

Perhaps if I get this to work I can submit a doc to the linux-ha folks to
save others like me the trouble...

Thanks a ton!

________________________________________
Chip Burke
________________________________________


-----Original Message-----
From: Corey Edwards [mailto:tensai at zmonkey.org] 
Sent: Thursday, January 05, 2006 12:08 PM
To: cburke at innova-partners.com
Subject: RE: [DRBD-user] meta-disk

On Thu, 2006-01-05 at 11:55 -0500, Chip Burke wrote:
> Hrm, back to the drawing board then. What is a typical situation then? For
> instance, if I make a change to httpd.conf on one machine in the cluster,
is
> there a way for it to automatically update on the other machine so if it
has
> to take over the configs are correct? I am certain I am missing something
> being a newbie at this. Is Heartbeat the answer for the above? 
> 
> So is a more typical situation:
> 
> Use drbd to replicate /usr /home /var
> 
> Then heartbeat does something to keep the /etc/ type things in sync? Sorry
> to be so dense here. I know the tools involved, just not exactly where
each
> one comes into play. Again, the end goal is essentially to have a fail
over
> box that automatically kicks in and operates exactly as its primary in
case
> of the primary failure.

It depends on the situation, of course. For us, we're replicating a mail
spool and the mail server configuration changes very infrequently. So a
simple cron job to copy the config into the DRBD data spool is all I
have set up. Any other changes (system upgrades, etc.) I just make on
both hosts. We only have a couple DRBD clusters, so that's not bad.

You might check into Csync2, also from Linbit, which can keep
configuration files in sync (as the name implies). I haven't personally
used it, but I know there are many on the DRBD list who have.

        http://oss.linbit.com/csync2/
        
I've also heard of Cfengine, which is a cluster configuration management
tool. I tried setting it up once but talk about complicated. That was a
few years ago, before I met DRBD.

        http://www.cfengine.org/

As for heartbeat, I'm not an expert on that either. I don't think it can
handle the config files but as you pointed out, the docs are very sparse
so who really knows?

Corey