I'm planning on moving over roughly 300 web sites to my cPanel server over the next few weeks. I plan on moving the web sites in four stages. Can someone review the steps as planned below and let me know if there is anything wrong with this plan?
Step 1. Setup a new account for each domain on the cPanel server and point the A records to the IP address for each domain on the old servers (each account there has a dedicated IP). Lower the TTL's to 10 min.
Step 2. Change my private nameservers to point to the cPanel server. After this change, all domains should continue to point to their account on the old servers without any downtime.
Step 3. Start migrating web sites. After each migration, change the A record for that domain to point back to the cPanel server.
Step 4. Close down the old servers.
I'm nervous about Step #2 because if there are any problems with the 'A Record' forwarding then all sites will be down.