If you modify the PGDATA directory, an error is reported when creating a Seondary Node. And the same operation is normal when creating Primary Node.

[z3473]

-bash-4.2$ pg_autoctl create postgres --hostname 192.168.2.116 --auth trust --no-ssl --monitor 'postgres://autoctl_node@192.168.2.114:5432/pg_auto_failover?sslmode=prefer' 14:32:15 1541 WARN No encryption is used for network traffic! This allows an attacker on the network to read all replication data. 14:32:15 1541 WARN Using --ssl-self-signed instead of --no-ssl is recommend to achieve more security with the same ease of deployment. 14:32:15 1541 WARN See https://www.postgresql.org/docs/current/libpq-ssl.html for details on how to improve 14:32:15 1541 INFO Using default --ssl-mode "prefer" 14:32:15 1541 INFO Started pg_autoctl postgres service with pid 1543 14:32:15 1541 INFO Started pg_autoctl node-init service with pid 1544 14:32:15 1543 INFO /usr/pgsql-12/bin/pg_autoctl do service postgres --pgdata /data/pg -v 14:32:15 1544 INFO Registered node 8 (192.168.2.116:5432) with name "node_8" in formation "default", group 0, state "wait_standby" 14:32:15 1544 INFO Writing keeper state file at "/var/lib/pgsql/.local/share/pg_autoctl/data/pg/pg_autoctl.state" 14:32:15 1544 INFO Writing keeper init state file at "/var/lib/pgsql/.local/share/pg_autoctl/data/pg/pg_autoctl.init" 14:32:15 1544 INFO Successfully registered as "wait_standby" to the monitor. 14:32:15 1544 INFO FSM transition from "init" to "wait_standby": Start following a primary 14:32:15 1544 INFO Transition complete: current state is now "wait_standby" 14:32:15 1544 INFO New state for node 7 "node_7" (192.168.2.115:5432): single ➜ wait_primary 14:32:15 1544 INFO New state for node 7 "node_7" (192.168.2.115:5432): wait_primary ➜ wait_primary 14:32:15 1544 INFO Still waiting for the monitor to drive us to state "catchingup" 14:32:15 1544 WARN Please make sure that the primary node is currently running pg_autoctl run and contacting the monitor. 14:32:15 1544 INFO FSM transition from "wait_standby" to "catchingup": The primary is now ready to accept a standby 14:32:15 1544 INFO Initialising PostgreSQL as a hot standby 14:32:15 1544 INFO /usr/pgsql-12/bin/pg_basebackup -w -d application_name=pgautofailover_standby_8 host=192.168.2.115 port=5432 user=pgautofailover_replicator sslmode=prefer --pgdata /data/backup/node_8 -U pgautofailover_replicator --verbose --progress --max-rate 100M --wal-method=stream --slot pgautofailover_standby_8 14:32:15 1544 INFO pg_basebackup: initiating base backup, waiting for checkpoint to complete 14:32:15 1544 INFO pg_basebackup: checkpoint completed 14:32:15 1544 INFO pg_basebackup: write-ahead log start point: 0/2000028 on timeline 1 14:32:15 1544 INFO pg_basebackup: starting background WAL receiver 14:32:15 1544 INFO 0/25322 kB (0%), 0/1 tablespace (/data/backup/node_8/backup_label ) 14:32:15 1544 INFO 25332/25332 kB (100%), 0/1 tablespace (.../backup/node_8/global/pg_control) 14:32:15 1544 INFO 25332/25332 kB (100%), 1/1 tablespace
14:32:15 1544 INFO pg_basebackup: write-ahead log end point: 0/2000138 14:32:15 1544 INFO pg_basebackup: waiting for background process to finish streaming ... 14:32:15 1544 INFO pg_basebackup: syncing data to disk ... 14:32:16 1544 INFO pg_basebackup: base backup completed 14:32:16 1541 WARN pg_autoctl service node-init failed with exit status 0 14:32:16 1543 INFO Postgres controller service received signal SIGTERM, terminating 14:32:16 1541 INFO Stop pg_autoctl -bash-4.2$ ll /data/pg/ total 0

Active: active (running) since Sun 2023-06-25 14:36:49 CST; 2s ago Main PID: 1637 (pg_autoctl) CGroup: /system.slice/postgresprimary.service ├─1637 /usr/pgsql-12/bin/pg_autoctl run ├─1639 pg_autoctl: start/stop postgres ├─1649 /usr/pgsql-12/bin/pg_autoctl do service node-active --pgdata /data/pg -v └─1651 /usr/pgsql-12/bin/pg_basebackup -w -d application_name=pgautofailover_standby_8 host=192.168.2.115 port=5432 user=pgautofailover_replicator ssl...

Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 WARN The pg_autoctl create did not complete, completing now. Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO Continuing from a previous pg_autoctl create failed attempt Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO PostgreSQL state at registration time was: PGDATA does not exists Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO FSM transition from "wait_standby" to "catchingup": The primary is now ready ... standby Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO Initialising PostgreSQL as a hot standby Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO /usr/pgsql-12/bin/pg_basebackup -w -d application_name=pgautofailover_standby_8 host... Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO pg_basebackup: initiating base backup, waiting for checkpoint to complete Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO pg_basebackup: checkpoint completed Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO pg_basebackup: write-ahead log start point: 0/D000028 on timeline 1 Jun 25 14:36:51 localhost.localdomain pg_autoctl[1637]: 14:36:51 1649 INFO pg_basebackup: starting background WAL receiver Hint: Some lines were ellipsized, use -l to show in full. [root@localhost pgsql]# ll /data/ backup/ pg/
[root@localhost pgsql]# ll /data/pg/ total 0