With the 32-bit phase-out being announced, I'm looking at getting moved to 64-bit sooner rather than later.

To minimize interruption, I'd like to install another server and put it in a multi-server configuration (LDAP/MTA/mailbox/etc), slowly migrate all accounts from the original 32-bit server to the new 64-bit server, remove the original 32-bit server from the multi-server setup, leaving a single 64-bit server.

I will be using a combination of DNS plus the proxy (nginx) to make sure requests get sent to the correct server.

It should be trivial to remove the mailbox/mta servers, and I found the instructions for uninstalling a LDAP replica - so that doesn't seem like it should be a problem either.

Does anyone see anything that may cause an issue with this?