CentOS and yum repo differences across multi-machines

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Joined: 2014/08/28 15:43:04

CentOS and yum repo differences across multi-machines

Postby seven » 2014/08/28 15:50:35

I have two CentOS platforms. Both run "CentOS release 5.10 (Final)". One is a "real" machine and the other is a VM. Both are 64 bit. Call the real machine Prod and the VM Spare.

When I got this gig I was told that the two machines were identical. Spare is supposed to be a hot spare for Prod. It is now obvious that is not true. The two machines have different yum repo lists. There are duplicate looking install packages from different channels. Prod looks like a server. Spare looks like it had been somebody's desktop with Evolution, OpenOffice and other desktop cruft.

Prod and Spare have similar applications installed but found in different repos so the available yum update levels are different.

I have tried disabling the non-standard repos and uninstalling the non-standard packages. This has led to tears as removing X-Windows, for example, has led to the removal of hundreds of dependant modules that in turn have dependants which, in the end, made Spare deaf, blind and mute. Blessedly we had a copy of the VM.

My latest idea is to migrate both machines to the latest stable CentOS level and basically have a do-over. The downside (I think) is the downtime to the production machine and unknown custom software vs new package level issues.

My basic question is, what is the best way to make the platforms as identical as possible, and minimize (or better yet negate) downtime.

How should we maintain packages and other installs across them into the future? I am aware of Puppet, Chief and cfengine but have not used them before. Are these the way to go for the future? Something else?