http://blog.csdn.net/daniel_ustc/article/details/9395971
http://www.opsers.org/server/linux-automatically-backup-the-mysql-shell-script-on-a-regular-basis.html
工作原理是使用mysql的mysqldump工具来导出数据库为.sql文件，然后将所有导出的文件打包归档。
然后我们在shell脚本中使用 scp命令把备份文件复制到另外一台备份机器。
一，备份脚本
#!/bin/sh
# mysql_backup.sh: backup mysql databases and keep newest 5 days backup.
#
# db_user is mysql username
# db_passwd is mysql password
# db_host is mysql host
# —————————–
db_user="root"
db_passwd="ocs"
db_host="localhost"
# the directory for story your backup file.
backup_dir="/home/backup/"
# date format for backup file (dd-mm-yyyy)
time="$(date +"%Y-%m-%d_%H_%M_%S")"
today="$(date +"%Y-%m-%d")"
fpath=$backup_dir$today
echo $fpath
if [ ! -d $fpath ];then
mkdir $fpath
fi
# mysql, mysqldump and some other bin's path
MYSQL="/usr/bin/mysql"
MYSQLDUMP="/usr/bin/mysqldump"
MKDIR="/bin/mkdir"
RM="/bin/rm"
MV="/bin/mv"
GZIP="/bin/gzip"
# the directory for story the newest backup
test ! -d "$backup_dir/bk/" && $MKDIR "$backup_dir/bk/"
# check the directory for store backup is writeable
test ! -w $backup_dir && echo "Error: $backup_dir is un-writeable." && exit 0
# get all databases
all_db="$($MYSQL -u $db_user -h $db_host -p$db_passwd -Bse 'show databases')"
for db in $all_db
do
$MYSQLDUMP -u $db_user -h $db_host -p$db_passwd $db --single-transaction | $GZIP -9 > "$fpath/$db.$time.gz"
done
#
cd $backup_dir
tar czf Mysql.$time.tar.gz $today
rm -rf $today
mv Mysql.$time.tar.gz $backup_dir/bk/
#scp to other server
scp $backup_dir/bk/Mysql.$time.tar.gz root@172.16.86.1:/var/www/html/work/bak/
# delete the oldest backup
#find $backup_dir -type f -mtime +4 -name "*.gz" -exec rm -f {} \;
find $backup_dir/bk -name "*.gz" -type f -mtime +5 -exec rm -f {} \; > /dev/null 2>&1
exit 0;
二，排程
由于机器本身没有安装cron服务，透过yum先安装
# yum install vixie-cron
# yum install crontabs
说明：
vixie-cron软件包是cron的主程序；
crontabs软件包是用来安装、卸装、或列举用来驱动 cron 守护进程的表格的程序。
安装vixie-cron时，一般会自动加载安装crontabs
加入开机自动启动:
#chkconfig --level 35 crond on
#/sbin/service crond start
三，设置排程
#vi /etc/crontab
#backup mysql db
3 0 * * * root /home/backup/mysql_backup_wht.sh
四，设置scp
本机执行
# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
/root/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase): 回车空密码
Enter same passphrase again: 回车空密码
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
56:68:73:d4:be:a1:fe:4f:f6:9b:d9:a2:75:o1:d0:a0 root@ng
The key's randomart image is:
+--[ RSA 2048]----+
...
+-----------------+
#cd ~/.ssh
# scp id_rsa.pub root@172.16.1.1:/root/.ssh/authorized_keys
五，恢复数据库
恢复数据备份文件：
非压缩备份文件恢复：
#mysql -u root -p databasename < name2008010103.sql
从压缩文件直接恢复：
# zcat mrbs.2014-04-22_16_16_32.gz | mysql -uroot -ppassword -Dmrbs
其它问题：
# ./mysql_backup.sh
mysqldump: Got error: 1044: Access denied for user 'root'@'localhost' to database 'information_schema' when using LOCK TABLES
指令增加如下:
$MYSQLDUMP -u $db_user -h $db_host -p$db_passwd $db --single-transaction | $GZIP -9 > "$fpath/$db.$time.gz"
--single-transaction
或
--skip-lock-tables