Moving ID server functionality to a new/different repserver ...
The 'supported' method is to drop your replication system and rebuild from scratch with a new ID server. Having said that, there is an unsupported method that isn't too tough as long as you pay attention to the details.
NOTE: To minimize risk you may want to consider just moving the ID server to a new machine (ie, follow 'normal' procedures for moving a repserver between machines). I've got a separate post (below) that addresses the stable queue issue when moving a repserver between machines.
I've used the following procedure a few times to move ID server functionality to a new ID repserver:
NOTE: Assumes the new repserver has already been created and is up and running
- create an id user in the new repserver (create user/set password)
- shutdown all repservers
- update all repserver config files to point to the new ID server (change ID_server/ID_user/ID_pw fields)
- update all RSSDs to reference new ID server: update rs_config set charvalue = '<NewIDServerName>' where optionname = 'id_server'
- in new ID server's RSSD: delete rs_version/rs_idnames/rs_ids, then copy data for these tables from old ID server's RSSD to new ID server's RSSD
- start up repservers; make sure they have no messages in their errorlog about not being able to find the ID server; address issues as appropriate (eg, update repserver config file, update interfaces file with new ID server's address, etc) to make sure the repserver can find the ID server during start up; do not continue to the next step until you've verified the repserver can connect to the ID server during start up
- make sure each repserver can communicate with the new ID server by adding a new database connection, verify new database shows up in new ID server's RSSD/rs_idnames table, drop the new database connection, verify new database removed from new ID server's RSSD/rs_idnames table
NOTE: I'd suggest performing these steps before you configure the new ID repserver with any routes, database connections, repdefs, subscriptions, etc.