cd /mnt
mkdir dbback
pwd
/mnt/dbback

vim bcmysql.sh

#!/bin/bash
mysqldump -uusername -ppassword demo > /mnt/dbback/demo_$(date +%Y%m%d_%H%M%S).sql

#!/bin/bash
mysqldump -uusername -ppassword demo | gzip > /mnt/dbback/demo_$(date +%Y%m%d_%H%M%S).sql.gz

chmod u+x bcmysql.sh

vim /etc/my.cnf

[mysqldump]
user=your_backup_user_name
password=your_backup_password

demo_20181114_193425.sql

--default-character-set=gbk

show variables like '%char%'; 
-- 查询结果
character_set_client utf8
character_set_connection utf8
character_set_database utf8mb4
character_set_filesystem binary
character_set_results utf8
character_set_server utf8
character_set_system utf8
character_sets_dir /usr/local/mysql/share/charsets/

--hex-blob

mysqldump --default-character-set=utf8 --hex-blob demo > /mnt/dbback/demo_$(date +%Y%m%d_%H%M%S).sql

# crontab
-bash: crontab: command not found

# yum -y install vixie-cron

[root@iZ2zeck5vZ ~]# crontab -help
crontab：无效选项 -- h
crontab: usage error: unrecognized option
Usage:
crontab [options] file
crontab [options]
crontab -n [hostname]
Options:
-u <user> define user
-e edit user's crontab
-l list user's crontab
-r delete user's crontab
-i prompt before deleting
-n <host> set host in cluster to run users' crontabs
-c get host in cluster to run users' crontabs
-s selinux context
-x <mask> enable debugging
Default operation is replace, per 1003.2

crontab -e

*/1 * * * * /mnt/dbback/bcmysql.sh

0 1 * * * /mnt/dbback/bcmysql.sh

# tail -f /var/log/cron