While doing linux timed execution tasks, I found that this command was not found, so I needed to install it. The installation steps are as follows:
[root@dzwww ~]# yum install -y vixie-cron
....
Installed:
vixie-cron.i386 4:4.1-81.el5
Complete!
After the installation is complete, start the service:
service crond start
Restart the service:
/sbin/service crond restart or /etc/rc.d/init.d/crond restart
crontab -u //Set the cron service of a user, generally the root user needs this parameter when executing this command
crontab -l //List the details of a user's cron service
crontab -r //delete a user's cron service
crontab -e //Edit a user's cron service
//For example, root checks its own cron settings
crontab -u root -l
Configuration file directory /var/spool/cron
//Execute mysqlback.sh at 12:00 every day
vi /etc/crontab
00 12 * * * root /usr/local/mysqlback.sh
00 10 * * * root /data/db/backup/backup.sh #10 AM
00 01 * * * root /data/db/backup/backup.sh #3AM
vi backup.sh
rq=` date +%Y%m%d%H%M%S`
mysqldump -uroot -paaa dddsdudb>/data/db/backup/abc_$rq.sql