Hi,
gtm_add is indeed the way to do this. (It's a bit strange that this has to be done via CLI - not sure why there's still not a GUI button for this ;)
Some things to look out for;
- Backups of both sides... you never know! ;)
- Check that both systems are running the same software version and NTP.
- Add the system that you are about to add to the existing GTM infrastructure. (Under DNS - GSLB - Servers) This will ensure that the GTM's know where they are logically located.
- Run gtm_add from the NEW system - it pulls in the configuration from the existing member you connect to. If you run this from an existing GTM, you will end up with a nice empty config...
- Once the services are finished restarting, check that the new GTM now contains the same GSLB config and that it's showing as green in the old GTM system
- Note that some elements are NOT synced (such as DNS listeners)
You can also find more details here: https://support.f5.com/csp/article/K45907236
Hope this helps.
Cirrus
