RE: [TCLUG:6161] secondary linux server project

["Carl Patten" <cpatte@trimodalinc.com>]

>
> Some secure way to syncing files that will not transfer files that haven't
> been modified. Hopefully something that isn't very bandwidth intensive so
> it could be updated everyone hour or so.

rsync does all that.  Available at rufus.w3.org or any other rpm collection.
A lot of sites use it for mirroring.  You can set it to never overwrite
newer files.

I like your idea of using the run level to determine the server's behavior.
If you set the primary server to run level 3 and the secondary to run level
2, all the reconfiguring can be done via boot scripts.  What's more, you
could set both servers to initially boot to run level 2, then check for a
primary server and proceed to 3 if one is not available.

Just to be stunningly original, let's call the primary server Caesar and the
backup server Brutus.  The backup server always pings the primary to see if
its up.  If the ping fails three times, Brutus promotes itself by going into
run level 3 (/sbin/init 3), acquiring Caesar's configuration.

Ok, now Caesar comes back up.  It sees there's already a primary server, so
it stays in backup mode and syncs until someone shuts down Brutus.  Then
Caesar promotes itself to primary, and Brutus can come up in backup mode.

This process, incidentally, is very similar to how Windows NT handles
primary and secondary domain controllers.

You may also want to check the "Ask Slashdot" section at www.slashdot.org as
I believe this question was asked there a few weeks ago.

> Anyone have any ideas on the best way to go about this, or want to help or
> anything?

Sure I'll help, as long as it's not this weekend.  Got some vacation, ya
know.

--
Carl Patten
Systems Administrator
Trimodal Inc.