Not running - Active: active (exited)

Question

Linux Mint 20.2

Postgresql 9.6.

Steps:

sudo systemctl enable postgresql.service

Result:

Synchronizing state of postgresql.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable postgresql

Then restart service like this:

sudo service postgresql restart

And when check status like this:

service postgresql status

I get this:

postgresql.service - PostgreSQL RDBMS
     Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled)
     Active: active (exited) since Wed 2021-08-04 17:33:34 EEST; 47s ago
    Process: 29261 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
   Main PID: 29261 (code=exited, status=0/SUCCESS)

Why service is EXITED ?

here content of /var/log/postgresql/postgresql-9.6-main.log

2021-08-05 14:59:14.739 EEST [116538] LOG:  database system was shut down at 2021-08-05 14:59:13 EEST
2021-08-05 14:59:14.741 EEST [116538] LOG:  MultiXact member wraparound protections are now enabled
2021-08-05 14:59:14.746 EEST [116537] LOG:  database system is ready to accept connections
2021-08-05 14:59:14.746 EEST [116542] LOG:  autovacuum launcher started
2021-08-05 14:59:15.210 EEST [116544] [unknown]@[unknown] LOG:  incomplete startup packet
2021-08-05 14:59:55.996 EEST [116537] LOG:  received fast shutdown request
2021-08-05 14:59:55.996 EEST [116537] LOG:  aborting any active transactions
2021-08-05 14:59:55.997 EEST [116542] LOG:  autovacuum launcher shutting down
2021-08-05 14:59:55.998 EEST [116539] LOG:  shutting down
2021-08-05 14:59:56.037 EEST [116537] LOG:  database system is shut down
2021-08-05 14:59:57.069 EEST [119294] LOG:  database system was shut down at 2021-08-05 14:59:56 EEST
2021-08-05 14:59:57.072 EEST [119294] LOG:  MultiXact member wraparound protections are now enabled
2021-08-05 14:59:57.073 EEST [119299] LOG:  autovacuum launcher started
2021-08-05 14:59:57.073 EEST [119290] LOG:  database system is ready to accept connections
2021-08-05 14:59:57.549 EEST [119301] [unknown]@[unknown] LOG:  incomplete startup packet
2021-08-05 15:03:46.004 EEST [119290] LOG:  received fast shutdown request
2021-08-05 15:03:46.004 EEST [119290] LOG:  aborting any active transactions
2021-08-05 15:03:46.004 EEST [119299] LOG:  autovacuum launcher shutting down
2021-08-05 15:03:46.005 EEST [119296] LOG:  shutting down
2021-08-05 15:03:46.018 EEST [119290] LOG:  database system is shut down
2021-08-05 15:03:47.070 EEST [119631] LOG:  database system was shut down at 2021-08-05 15:03:46 EEST
2021-08-05 15:03:47.072 EEST [119631] LOG:  MultiXact member wraparound protections are now enabled
2021-08-05 15:03:47.074 EEST [119630] LOG:  database system is ready to accept connections
2021-08-05 15:03:47.074 EEST [119639] LOG:  autovacuum launcher started
2021-08-05 15:03:47.557 EEST [119642] [unknown]@[unknown] LOG:  incomplete startup packet

here another command:

pg_lsclusters

Ver Cluster Port Status Owner    Data directory               Log file
9.6 main    5432 online postgres /var/lib/postgresql/9.6/main /var/log/postgresql/postgresql-9.6-main.log

one more command:

sudo pg_isready
/var/run/postgresql:5432 - accepting connections

Answer 1

Ubuntu 22.04

sudo apt install -y libpq-dev postgresql postgresql-contrib

Here is the result

$ systemctl status postgresql
● postgresql.service - PostgreSQL RDBMS
 Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor    preset: enabled)
 Active: active (exited) since Sun 2022-08-14 14:49:01 CEST; 19min ago
 Main PID: 56596 (code=exited, status=0/SUCCESS)
    CPU: 5ms

 Aug 14 14:49:01 MYHOSTNAME systemd[1]: Starting PostgreSQL RDBMS...
 Aug 14 14:49:01 MYHOSTNAME systemd[1]: Finished PostgreSQL RDBMS.

$ psql --version
psql (PostgreSQL) 14.4 (Ubuntu 14.4-0ubuntu0.22.04.1)

$ pg_lsclusters
Ver Cluster Port Status Owner    Data directory              Log file
14  main    5432 online postgres /var/lib/postgresql/14/main /var/log/postgresql/postgresql-14-main.log

$ systemctl status postgresql@14-main
● [email protected] - PostgreSQL Cluster 14-main
 Loaded: loaded (/lib/systemd/system/[email protected]; enabled-runtime; vendor preset: enabled)
 Active: active (running) since Sun 2022-08-14 14:49:01 CEST; 28min ago
Main PID: 56568 (postgres)
  Tasks: 7 (limit: 19013)
 Memory: 28.8M
    CPU: 1.287s
 CGroup: /system.slice/system-postgresql.slice/[email protected]
         ├─56568 /usr/lib/postgresql/14/bin/postgres -D /var/lib/postgresql/14/main -c config_file=/etc/postgresql/14/main/postgresql.conf
         ├─56570 "postgres: 14/main: checkpointer " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" >
         ├─56571 "postgres: 14/main: background writer " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" ">
         ├─56572 "postgres: 14/main: walwriter " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" >
         ├─56573 "postgres: 14/main: autovacuum launcher " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "">
         ├─56574 "postgres: 14/main: stats collector " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" >
         └─56575 "postgres: 14/main: logical replication launcher " "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "" "">

So In your case : systemctl status [email protected] should display postgres active and running