I have 5 mongo servers in a replica set: zuemongo1, 2, 5, 6, and 7.

MMS currently shows their versions as 2.2.1, 2.2.5, 2.2.1, 2.2.5, 2.2.5 (respectively).

The active daemon running on all five servers is 2.2.1.

Last night, I did some maintenance on this replicaset, and so knowing (a) I was going to bounce the dameon on each server and (b) we need to upgrade to 2.2.5 soon, I took last night as an opportunity to get the 2.2.5 binaries on the servers, but set them aside (details below) so i can upgrade and downgrade at will (details below) when we're ready for the upgrade.

What's odd is that MMS thinks we're running 2.2.5 on 3 servers and 2.2.1 on 2 servers ... when in reality i executed the exact same commands on all five servers.

Yesterday, I stopped mongod:
$ /etc/init.d/mongod stop

Yum upgraded to 2.2.5:
$ yum update mongo-10gen-2.2.5 mongo-10gen-server-2.2.5

But then mv'd all of the 2.2.5 binaries aside, e.g.:
$ cd /usr/bin
$ mv mongo mongo.2.2.5
$ mv mongod mongod.2.2.5
$ mv mongodump mongodump.2.2.5
$ mv mongoexport mongoexport.2.2.5
$ mv mongofiles mongofiles.2.2.5
$ mv mongoimport mongoimport.2.2.5
$ mv mongooplog mongooplog.2.2.5
$ mv mongoperf mongoperf.2.2.5
$ mv mongorestore mongorestore.2.2.5
$ mv mongos mongos.2.2.5
$ mv mongostat mongostat.2.2.5
$ mv mongotop mongotop.2.2.5
$ mv bsondump bsondump.2.2.5

And sym linkd the 2.2.1 binaries (which is what we've been running on):
$ ln -sf mongo.2.2.1 mongo
$ ln -sf mongod.2.2.1 mongod
$ ln -sf mongodump.2.2.1 mongodump
$ ln -sf mongoexport.2.2.1 mongoexport
$ ln -sf mongofiles.2.2.1 mongofiles
$ ln -sf mongoimport.2.2.1 mongoimport
$ ln -sf mongooplog.2.2.1 mongoimport
$ ln -sf mongoperf.2.2.1 mongoperf
$ ln -sf mongorestore.2.2.1 mongorestore
$ ln -sf mongos.2.2.1 mongos
$ ln -sf mongostat.2.2.1 mongostat
$ ln -sf mongotop.2.2.1 mongotop
$ ln -sf bsondump.2.2.1 bsondump

Then started mongod back up:
$ /etc/init.d/mongod start

So my incredibly trivial question is: how does MMS get it's version info? I'm guessing it's not from the running daemon but possibly via a YUM post-install hook or some YUM meta-data somewhere.

Thanks
--tom