Recently in a conversation a question came up if anyone used
rdist(1), as I long time user I said I
did. The inevitable question then became what I used it for, which
then turned into “you should write a blog post about this”. So here
we are.
To quote the manual for rdist it’s “a program to maintain identical
copies of files over multiple hosts”, which is exactly what it does.
My primary use for it is that I have a firewall cluster using
carp(4) for fail over. Now that works
great, I can pull the power on the primary firewall and it gracefully
fails over to the backup host without so much as a lost ping. Users
are never the wiser. However I do need to ensure that all services run
on both hosts and they have identical config files so things don’t
start going wonky when the backup host becomes the primary. This is
where rdist comes in.
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