The final stages involve:
On February 2nd, we will conduct an initial incremental rsync. This will copy over all data that is new or that has changed since the bulk of the data was moved over. We will be checking and double checking the configuration on all of the servers to ensure that everything is correct.
On February 3rd, we will conduct a final rsync and migrate any data that has changed within the past 24 hours over. We are then going to disable all services on the old server and copy over all the DNS zone files from the new server to the old server. We will then restart just the DNS service on the old server, which will mean all DNS requests will be forwarded to the new server which has the up to date data on it.
You can expect up to 30 minutes downtime whilst we copy the DNS zones from the new server to the old server. We have elected to use a small amount of downtime to ensure there are no discrepancies between data on the new and old server. The window in which this downtime will occur is between 12:00 GMT on February 3rd and 00:00 GMT on February 4th. In practice, we expect the downtime to be a matter of minutes but we are allowing ourselves upto 30 minutes incase of any unforeseen problems.