Patroni: How does patroni recognizes to which cluster belongs pg_data folder?

[filipp-filippov]

Hi, i have configured patroni cluster with master/slave node.
I'd like to migrate data from another postgres cluster (not patroni) to current patroni cluster. I'd like to do that just by mounting folder with data that i need to patroni's pg_data folder but unfortunately when i'm doing that i'm getting an error that sounds like :
system ID mismatch, node $NODENAME belongs to a different cluster
Where does patroni stores that data?

So is there any workaround to do that in this way?
P.S. i don't like to use pg_dump/pg_restore way to do this.

[CyberDem0n]

Patroni stores information about Database system identifier in the DCS.
If you try to start Patroni with the wrong data directory, it will notice it and refuse to work.

You have to options:

1. Set a different scope in the configuration.
2. Use patronictl remove <scope> to remove information about the cluster from DCS before starting up the Patroni.

[filipp-filippov]

@CyberDem0n Thanks a lot for explanation! It worked for me !