1 前言

一个问题，一篇文章，一出故事。
笔者今天完成最新版本的PostgreSQL服务端的安装配置，现在需要完成修改数据库默认存储的测试。

2 最佳实践

2.1 测试环境

如何部署Oracle Linux 9.x PostgreSQL？

2.2 迁移操作

2.2.1 停止服务

systemctl stop postgresql.service

2.2.2 迁移数据目录

mkdir -p /data
mv /var/lib/pgsql/data /data/pgsql
ln -s /data/pgsql /var/lib/pgsql/data

2.2.3 修改服务控制脚本（可选）

vim /usr/lib/systemd/system/postgresql.service

配置修改如下，

# It's not recommended to modify this file in-place, because it will be
# overwritten during package upgrades.  It is recommended to use systemd
# "dropin" feature;  i.e. create file with suffix .conf under
# /etc/systemd/system/UNITNAME.service.d directory overriding the
# unit's defaults.  Look at systemd.unit(5) manual page for more info.

[Unit]
Description=PostgreSQL database server
After=network.target

[Service]
Type=notify

User=postgres
Group=postgres

# Where to send early-startup messages from the server (before the logging
# options of postgresql.conf take effect)
# This is normally controlled by the global default set by systemd
# StandardOutput=syslog

# Disable OOM kill on the postmaster
OOMScoreAdjust=-1000
# ... but allow it still to be effective for child processes
# (note that these settings are ignored by Postgres releases before 9.5)
Environment=PG_OOM_ADJUST_FILE=/proc/self/oom_score_adj
Environment=PG_OOM_ADJUST_VALUE=0

Environment=PGDATA=/data/pgsql

ExecStartPre=/usr/libexec/postgresql-check-db-dir %N
# Even though the $PGDATA variable is exported (postmaster would accept that)
# use the -D option here so PGDATA content is printed by /bin/ps and by
# 'systemctl status'.
ExecStart=/usr/bin/postmaster -D ${PGDATA}
ExecReload=/bin/kill -HUP $MAINPID
KillMode=mixed
KillSignal=SIGINT

# No artificial start/stop timeout (rhbz#1525477, pgrpms#2786).
TimeoutSec=0

[Install]
WantedBy=multi-user.target   

配置修改后，你需要执行如下命令重载服务使配置生效，

systemctl daemon-reload

2.2.4 启动服务

systemctl start postgresql.service