PostgreSQL-pg_ctl

命令简介

pg_ctl 启动、关闭、重启 postgres

pg_ctl start [-w] [-s] [-D datadir] [-l filename] [-o options] [-p path]
pg_ctl stop [-W] [-s] [-D datadir] [-m s[mart] | f[ast] | i[mmediate] ]
pg_ctl restart [-w] [-s] [-D datadir] [-m s[mart] | f[ast] | i[mmediate] ] [-o options]
pg_ctl reload [-s] [-D datadir]
pg_ctl status [-D datadir]
pg_ctl kill [signal_name] [process_id]
pg_ctl register [-N servicename] [-U username] [-P password] [-D datadir] [-w] [-o options]
pg_ctl unregister [-N servicename]

具体说明见参考资料。

实操记录

# 查找 pg_ctl
[root@localhost ~]# whereis pg_ctl
pg_ctl: /usr/bin/pg_ctl /usr/share/man/man1/pg_ctl.1.gz
 
# 启动 postgres
[root@localhost ~]# su postgres
bash-4.2$ /usr/bin/pg_ctl -D /var/lib/pgsql/data start
could not change directory to "/root"
pg_ctl: another server might be running; trying to start server anyway
server starting
bash-4.2$ FATAL:  lock file "postmaster.pid" already exists
HINT:  Is another postmaster (PID 30063) running in data directory "/var/lib/pgsql/data"?

出现如下错误  could not change directory to "/root"，因为在 postgres 中不能自动切换路径，解决方法

bash-4.2$ cd /usr/bin
bash-4.2$ pwd
/usr/bin
bash-4.2$ ./pg_ctl -D /var/lib/pgsql/data start
server starting

可能出现如下错误 pg_ctl: PID file "/var/lib/pgsql/data/postmaster.pid" does not exist，可以查看启动日志

我操作时是因为磁盘满了，无法创建新的文件 postmaster.pid，清除缓存腾出一点空间即可。