Hi,

We are currently on V 2.2.4 of MongoDB and is planning for an upgrade to 3.0. The recommended upgrade process that I could see from the wiki is

2.2.4->2.4->2.6->3.0.6

We would like to upgrade with minimum disruption to our live system. We would also like to fall back to our existing version quickly in the event of a critical issue during update.

We currently have 3 MongoDb servers(VM's) in replica setup.

The plan we have worked out is to

> Take Snapshot of Mongo Server 01 (on version 2.2.4)
> Power Off Mongo Server 02 and Mongo Server 03
> Upgrade Mongo Server 01 to version 2.4
> Provision new servers Mongo Server 04 and Mongo Server 05 to the replica set both on version 2.4
> Upgrade the now version 2.4 cluster to version 2.6
> Upgrade the now 2.6 cluster to version 3.0.6
>Remove MongoServer 02 and Mongo Server 03 from replica set

In the event off failure

> Shutdown Mongo Server 04 and Mongo Server 05
>Restore Snapshot of Mongo Server 01 and Power on Mongo Server 02 and Mongo Server 03

Can you see any issues with this upgrade plan. ?