Restart and Reload PostgreSQL Archives

How to START/STOP PostgreSQL 13 ON RHEL 7

Table of Contents
___________________________________________________________________________________________________

0. Overview
1. How to check Postgres server status?
2. How to Stop Postgres server?
3. How to Start Postgres server?
4. How to Restart Postgres server?
5. How to Reload Postgres server?
___________________________________________________________________________________________________

0. Overview

As root user:

service postgresql-13.service status
service postgresql-13.service start
service postgresql-13.service restart
service postgresql-13.service reload
service postgresql-13.service stop

OR 

systemctl stop postgresql-13.service
systemctl start postgresql-13.service
systemctl restart postgresql-13.service
systemctl status postgresql-13.service
systemctl reload postgresql-13.service

As Postgres user use pg_ctl command

/usr/pgsql-13/bin/pg_ctl stop -D /var/lib/pgsql/13/data
/usr/pgsql-13/bin/pg_ctl start -D /var/lib/pgsql/13/data
/usr/pgsql-13/bin/pg_ctl restart -D /var/lib/pgsql/13/data
/usr/pgsql-13/bin/pg_ctl status -D /var/lib/pgsql/13/data
/usr/pgsql-13/bin/pg_ctl reload -D /var/lib/pgsql/13/data

Restart or reload is required when changes are made to the postgresql.conf file.

Reload simply reloads the configuration in-memory. Restart replaces the entire instance.

1. How to check Postgres server status?

[root@rac1 ~]# systemctl list-units|grep postgresql
  postgresql-13.service     loaded active running   PostgreSQL 13 database server
[root@rac1 ~]# 

---- OR -----

[root@rac1 ~]# service postgresql-13.service status
Redirecting to /bin/systemctl status postgresql-13.service
● postgresql-13.service - PostgreSQL 13 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-13.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-03-15 17:57:05 +08; 53min ago
     Docs: https://www.postgresql.org/docs/13/static/
  Process: 969 ExecStartPre=/usr/pgsql-13/bin/postgresql-13-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 991 (postmaster)
   CGroup: /system.slice/postgresql-13.service
           ├─ 991 /usr/pgsql-13/bin/postmaster -D /var/lib/pgsql/13/data/
           ├─1053 postgres: logger
           ├─1178 postgres: checkpointer
           ├─1179 postgres: background writer
           ├─1180 postgres: walwriter
           ├─1181 postgres: autovacuum launcher
           ├─1182 postgres: stats collector
           ├─1183 postgres: logical replication launcher
           └─2282 postgres: postgres postgres [local] idle

Mar 15 17:57:03 rac1.rajasekhar.com systemd[1]: Starting PostgreSQL 13 database server...
Mar 15 17:57:04 rac1.rajasekhar.com postmaster[991]: 2021-03-15 17:57:04.155 +08 [991] LOG:  redirecting log output to logging collector process
Mar 15 17:57:04 rac1.rajasekhar.com postmaster[991]: 2021-03-15 17:57:04.155 +08 [991] HINT:  Future log output will appear in directory "log".
Mar 15 17:57:05 rac1.rajasekhar.com systemd[1]: Started PostgreSQL 13 database server.
[root@rac1 ~]#

--- OR ---

[root@rac1 ~]# ps -ef | grep postgres
postgres   991     1  0 17:57 ?        00:00:00 /usr/pgsql-13/bin/postmaster -D /var/lib/pgsql/13/data/
postgres  1053   991  0 17:57 ?        00:00:00 postgres: logger
postgres  1178   991  0 17:57 ?        00:00:00 postgres: checkpointer
postgres  1179   991  0 17:57 ?        00:00:00 postgres: background writer
postgres  1180   991  0 17:57 ?        00:00:00 postgres: walwriter
postgres  1181   991  0 17:57 ?        00:00:00 postgres: autovacuum launcher
postgres  1182   991  0 17:57 ?        00:00:00 postgres: stats collector
postgres  1183   991  0 17:57 ?        00:00:00 postgres: logical replication launcher
root      2201  2143  0 17:58 pts/0    00:00:00 su - postgres
postgres  2202  2201  0 17:58 pts/0    00:00:00 -bash
postgres  2281  2202  0 17:58 pts/0    00:00:00 psql
postgres  2282   991  0 17:58 ?        00:00:00 postgres: postgres postgres [local] idle
root      5744  5275  0 18:55 pts/1    00:00:00 grep --color=auto postgres
[root@rac1 ~]#

OR

[postgres@rac1 ~]$ cd /usr/pgsql-13/bin/
[postgres@rac1 bin]$ ./pg_ctl status -D /var/lib/pgsql/13/data/
pg_ctl: server is running (PID: 991)
/usr/pgsql-13/bin/postgres "-D" "/var/lib/pgsql/13/data/"
[postgres@rac1 bin]$

2. How to Stop Postgres server?

[postgres@rac1 ~]$ cd /usr/pgsql-13/bin/
[postgres@rac1 bin]$ ./pg_ctl stop -D /var/lib/pgsql/13/data/
waiting for server to shut down.... done
server stopped
[postgres@rac1 bin]$

[root@rac1 ~]# ps -ef | grep postgres
root      6718  2143  0 19:07 pts/0    00:00:00 grep --color=auto postgres
[root@rac1 ~]#

--- OR ----

[root@rac1 ~]# service postgresql-13.service stop
Redirecting to /bin/systemctl stop postgresql-13.service
[root@rac1 ~]#
[root@rac1 ~]# service postgresql-13.service status
Redirecting to /bin/systemctl status postgresql-13.service
● postgresql-13.service - PostgreSQL 13 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-13.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since Mon 2021-03-15 19:07:03 +08; 5min ago
     Docs: https://www.postgresql.org/docs/13/static/
  Process: 991 ExecStart=/usr/pgsql-13/bin/postmaster -D ${PGDATA} (code=exited, status=0/SUCCESS)
  Process: 969 ExecStartPre=/usr/pgsql-13/bin/postgresql-13-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 991 (code=exited, status=0/SUCCESS)

Mar 15 17:57:03 rac1.rajasekhar.com systemd[1]: Starting PostgreSQL 13 database server...
Mar 15 17:57:04 rac1.rajasekhar.com postmaster[991]: 2021-03-15 17:57:04.155 +08 [991] LOG:  redirecting log output to logging collector process
Mar 15 17:57:04 rac1.rajasekhar.com postmaster[991]: 2021-03-15 17:57:04.155 +08 [991] HINT:  Future log output will appear in directory "log".
Mar 15 17:57:05 rac1.rajasekhar.com systemd[1]: Started PostgreSQL 13 database server.
[root@rac1 ~]#

3. How to Start Postgres server?

[postgres@rac1 ~]$ cd /usr/pgsql-13/bin/
[postgres@rac1 bin]$ ./pg_ctl start -D /var/lib/pgsql/13/data/
waiting for server to start....2021-03-15 19:14:17.815 +08 [7443] LOG:  redirecting log output to logging collector process
2021-03-15 19:14:17.815 +08 [7443] HINT:  Future log output will appear in directory "log".
 done
server started
[postgres@rac1 bin]$

--- OR ---- 

[root@rac1 ~]# service postgresql-13.service start
Redirecting to /bin/systemctl start postgresql-13.service
[root@rac1 ~]#
[root@rac1 ~]# service postgresql-13.service status
Redirecting to /bin/systemctl status postgresql-13.service
● postgresql-13.service - PostgreSQL 13 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-13.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-03-15 19:15:14 +08; 3s ago
     Docs: https://www.postgresql.org/docs/13/static/
  Process: 7523 ExecStartPre=/usr/pgsql-13/bin/postgresql-13-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 7529 (postmaster)
   CGroup: /system.slice/postgresql-13.service
           ├─7529 /usr/pgsql-13/bin/postmaster -D /var/lib/pgsql/13/data/
           ├─7533 postgres: logger
           ├─7535 postgres: checkpointer
           ├─7536 postgres: background writer
           ├─7537 postgres: walwriter
           ├─7538 postgres: autovacuum launcher
           ├─7539 postgres: stats collector
           └─7540 postgres: logical replication launcher

Mar 15 19:15:14 rac1.rajasekhar.com systemd[1]: Starting PostgreSQL 13 database server...
Mar 15 19:15:14 rac1.rajasekhar.com postmaster[7529]: 2021-03-15 19:15:14.193 +08 [7529] LOG:  redirecting log output to logging collector process
Mar 15 19:15:14 rac1.rajasekhar.com postmaster[7529]: 2021-03-15 19:15:14.193 +08 [7529] HINT:  Future log output will appear in directory "log".
Mar 15 19:15:14 rac1.rajasekhar.com systemd[1]: Started PostgreSQL 13 database server.
[root@rac1 ~]#

4. How to Restart Postgres server?

-w, --wait             wait until operation completes (default)
  
[postgres@rac1 ~]$ cd /usr/pgsql-13/bin/
[postgres@rac1 bin]$ ./pg_ctl -w restart -D /var/lib/pgsql/13/data/
waiting for server to shut down.... done
server stopped
waiting for server to start....2021-03-15 19:22:58.920 +08 [8017] LOG:  redirecting log output to logging collector process
2021-03-15 19:22:58.920 +08 [8017] HINT:  Future log output will appear in directory "log".
 done
server started
[postgres@rac1 bin]$

--- OR ----

[root@rac1 ~]# service postgresql-13.service restart
Redirecting to /bin/systemctl restart postgresql-13.service
[root@rac1 ~]#
[root@rac1 ~]# service postgresql-13.service status
Redirecting to /bin/systemctl status postgresql-13.service
● postgresql-13.service - PostgreSQL 13 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-13.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-03-15 19:52:26 +08; 3s ago
     Docs: https://www.postgresql.org/docs/13/static/
  Process: 10439 ExecStartPre=/usr/pgsql-13/bin/postgresql-13-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 10445 (postmaster)
   CGroup: /system.slice/postgresql-13.service
           ├─10445 /usr/pgsql-13/bin/postmaster -D /var/lib/pgsql/13/data/
           ├─10449 postgres: logger
           ├─10451 postgres: checkpointer
           ├─10452 postgres: background writer
           ├─10453 postgres: walwriter
           ├─10454 postgres: autovacuum launcher
           ├─10455 postgres: stats collector
           └─10456 postgres: logical replication launcher

Mar 15 19:52:26 rac1.rajasekhar.com systemd[1]: Starting PostgreSQL 13 database server...
Mar 15 19:52:26 rac1.rajasekhar.com postmaster[10445]: 2021-03-15 19:52:26.856 +08 [10445] LOG:  redirecting log output to logging collector process
Mar 15 19:52:26 rac1.rajasekhar.com postmaster[10445]: 2021-03-15 19:52:26.856 +08 [10445] HINT:  Future log output will appear in directory "log".
Mar 15 19:52:26 rac1.rajasekhar.com systemd[1]: Started PostgreSQL 13 database server.
[root@rac1 ~]#

5. How to Reload Postgres server?

[postgres@rac1 bin]$ ./pg_ctl reload -D /var/lib/pgsql/13/data
server signaled
[postgres@rac1 bin]$

--- OR --- 

[root@rac1 ~]# service postgresql-13.service reload
Redirecting to /bin/systemctl reload postgresql-13.service
[root@rac1 ~]#
[root@rac1 ~]# service postgresql-13.service status
Redirecting to /bin/systemctl status postgresql-13.service
● postgresql-13.service - PostgreSQL 13 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-13.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-03-15 19:52:26 +08; 11min ago
     Docs: https://www.postgresql.org/docs/13/static/
  Process: 11218 ExecReload=/bin/kill -HUP $MAINPID (code=exited, status=0/SUCCESS)
  Process: 10439 ExecStartPre=/usr/pgsql-13/bin/postgresql-13-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)
 Main PID: 10445 (postmaster)
   CGroup: /system.slice/postgresql-13.service
           ├─10445 /usr/pgsql-13/bin/postmaster -D /var/lib/pgsql/13/data/
           ├─10449 postgres: logger
           ├─10451 postgres: checkpointer
           ├─10452 postgres: background writer
           ├─10453 postgres: walwriter
           ├─10454 postgres: autovacuum launcher
           ├─10455 postgres: stats collector
           └─10456 postgres: logical replication launcher

Mar 15 19:52:26 rac1.rajasekhar.com systemd[1]: Starting PostgreSQL 13 database server...
Mar 15 19:52:26 rac1.rajasekhar.com postmaster[10445]: 2021-03-15 19:52:26.856 +08 [10445] LOG:  redirecting log output to logging collector process
Mar 15 19:52:26 rac1.rajasekhar.com postmaster[10445]: 2021-03-15 19:52:26.856 +08 [10445] HINT:  Future log output will appear in directory "log".
Mar 15 19:52:26 rac1.rajasekhar.com systemd[1]: Started PostgreSQL 13 database server.
Mar 15 19:53:40 rac1.rajasekhar.com systemd[1]: Reloaded PostgreSQL 13 database server.
Mar 15 20:03:49 rac1.rajasekhar.com systemd[1]: Reloaded PostgreSQL 13 database server.
[root@rac1 ~]#

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Thank you,
Rajasekhar Amudala
Email: br8dba@gmail.com
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Linkedin: https://www.linkedin.com/in/rajasekhar-amudala/

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PostgreSQL DBA – How to START/STOP PostgreSQL 13 ON RHEL 7

How to START/STOP PostgreSQL 13 ON RHEL 7