how can i make mysql start automatically on linux?
Here are the complete steps to make sure mysql is started at boot time on RHEL4. They need to be run with root permission.
chkconfig --list mysqld
Unless you installed mysqld in a non-default way, this should show that mysqld is set to start at run levels 3,4 and 5:
mysqld 0:off 1:off 2:off 3:on 4:on 5:on 6:off
If this isn't the case, set up the correct run levels. If you didn't get any output from the previous command:
chkconfig --add mysqld
chkconfig --level 345 mysqld on
Finally, use chkconfig --list again to make sure you're set up correctly.