Linux/Centos/Ubuntu crontab备份数据库

1 前言

环境：Ubuntu。作为记录使用。

2 代码

2.1 脚本样例如下

# !/bin/sh
dd="$(date +"%Y%m%d%H%M%S")"
# 保存备份个数，备份31天数据
number=31
# 备份保存路径
backup_dir=/var/lib/mysql/backup
# 将要备份的数据库
database_name=sampleDBName
# 如果文件夹不存在则创建
if [ ! -d $backup_dir ];
then
mkdir -p $backup_dir;
fi
# 执行备份命令
/usr/bin/mysqldump --defaults-extra-file=/etc/mysql/conf.d/mysql.cnf sampleDBName>$backup_dir/$database_name-$dd.sql
# 写创建备份日志
echo "create $backup_dir/$database_name-$dd.dupm" >> $backup_dir/log.txt
# 找出需要删除的备份
delfile=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | head -1`
# 判断现在的备份数量是否大于$number
count=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | wc -l`
if [ $count -gt $number ]
then
# 删除最早生成的备份，只保留number数量的备份
rm $delfile
# 写删除文件日志
echo "delete $delfile" >> $backup_dir/log.txt
fi

2.2 crontab -l查看列表，-e 修改并使之生效

crontab -l
# Edit this file to introduce tasks to be run by cron.
# 
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
# 
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').# 
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
# 
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
# 
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
# 
# For more information see the manual pages of crontab(5) and cron(8)
# 
# m h  dom mon dow   command
0 1 * * * /bin/sh /var/lib/mysql/sh/dbBackup.sh

说明：代表每一天01:00分执行

3 结束语

略