Linux 服务器上的程序每天都在更新 MySQL 数据库，于是就想起写一个 shell 脚本，结合 crontab，定时备份数据库。其实非常简单，主要就是使用 MySQL 自带的 mysqldump 命令。
#!/bin/bash
# Shell script to backup MySql database
# To backup Nysql databases file to /backup dir and later pick up by your
# script. You can skip few databases from backup too.
# For more info please see (Installation info):
# http://www.cyberciti.biz/nixcraft/vivek/blogger/2005/01/mysql-backup-script.html
# Last updated: Aug - 2005
# --------------------------------------------------------------------
# This is a free shell script under GNU GPL version 2.0 or above
# Copyright (C) 2004, 2005 nixCraft project
# Feedback/comment/suggestions : http://cyberciti.biz/fb/
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
MyUSER="SET-MYSQL-USER-NAME" # USERNAME
MyPASS="SET-PASSWORD" # PASSWORD
MyHOST="localhost" # Hostname
# Linux bin paths, change this if it can not be autodetected via which command
MYSQL="$(which mysql)"
MYSQLDUMP="$(which mysqldump)"
CHOWN="$(which chown)"
CHMOD="$(which chmod)"
GZIP="$(which gzip)"
# Backup Dest directory, change this if you have someother location
DEST="/backup"
# Main directory where backup will be stored
MBD="$DEST/mysql"
# Get hostname
HOST="$(hostname)"
# Get data in dd-mm-yyyy format
NOW="$(date +"%d-%m-%Y")"
# File to store current backup file
FILE=""
# Store list of databases
DBS=""
# DO NOT BACKUP these databases
IGGY="test"
[ ! -d $MBD ] && mkdir -p $MBD || :
# Only root can access it!
$CHOWN 0.0 -R $DEST
$CHMOD 0600 $DEST
# Get all database list first
DBS="$($MYSQL -u $MyUSER -h $MyHOST -p$MyPASS -Bse 'show databases')"
for db in $DBS
do
skipdb=-1
if [ "$IGGY" != "" ];
then
for i in $IGGY
do
[ "$db" == "$i" ] && skipdb=1 || :
done
fi
if [ "$skipdb" == "-1" ] ; then
FILE="$MBD/$db.$HOST.$NOW.gz"
# do all inone job in pipe,
# connect to mysql using mysqldump for select mysql database
# and pipe it out to gz file in backup dir :)
$MYSQLDUMP -u $MyUSER -h $MyHOST -p$MyPASS $db | $GZIP -9 > $FILE
fi
done
保存后将以上脚本加入crontab调度。如：每天早上四点半备份：30 4 * * * /data/backup-db.sh
如果你使用mysql5.1，可能会提示mysqldump 错误:
mysqldump: Couldn't execute 'show create table `general_log`': Table 'mysql.general_log' doesn't exist mysqldump: Couldn't execute 'show create table `slow_log`': Table 'mysql.slow_log' doesn't exist
原因是mysql库中没有show_log表和general_log表，需要手动创建：
CREATE TABLE IF NOT EXISTS general_log ( event_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, user_host mediumtext NOT NULL, thread_id int(11) NOT NULL, server_id int(10) unsigned NOT NULL, command_type varchar(64) NOT NULL, argument mediumtext NOT NULL ) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log'; CREATE TABLE IF NOT EXISTS slow_log ( start_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, user_host mediumtext NOT NULL, query_time time NOT NULL, lock_time time NOT NULL, rows_sent int(11) NOT NULL, rows_examined int(11) NOT NULL, db varchar(512) NOT NULL, last_insert_id int(11) NOT NULL, insert_id int(11) NOT NULL, server_id int(10) unsigned NOT NULL, sql_text mediumtext NOT NULL ) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
