6 Quota

To install quota, we run this command:

yum install quota

Edit /etc/fstab and add ,usrquota,grpquota to the / partition (/dev/VolGroup00/LogVol00):

vi /etc/fstab

# This file is edited by fstab-sync - see 'man fstab-sync' for details
/dev/VolGroup00/LogVol00 /                       ext3    defaults,usrquota,grpquota        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /dev/shm                tmpfs   defaults        0 0
none                    /proc                   proc    defaults        0 0
none                    /sys                    sysfs   defaults        0 0
/dev/VolGroup00/LogVol01 swap                    swap    defaults        0 0
/dev/hdc                /media/cdrom            auto    pamconsole,exec,noauto,managed 0 0
/dev/fd0                /media/floppy           auto    pamconsole,exec,noauto,managed 0 0

Then run

touch /aquota.user /aquota.group
chmod 600 /aquota.*
mount -o remount /
quotacheck -avugm
quotaon -avug

to enable quota.

7 Install A Chrooted DNS Server (BIND9)

To install a chrooted BIND9, we do this:

yum install bind-chroot

Then do this:

chmod 755 /var/named/
chmod 775 /var/named/chroot/
chmod 775 /var/named/chroot/var/
chmod 775 /var/named/chroot/var/named/
chmod 775 /var/named/chroot/var/run/
chmod 777 /var/named/chroot/var/run/named/
cd /var/named/chroot/var/named/
ln -s ../../ chroot
chkconfig --levels 235 named on
/etc/init.d/named start

BIND will run in a chroot jail under /var/named/chroot/var/named/. I will use ISPConfig to configure BIND (zones, etc.).

8 MySQL (4.1)

To install MySQL, we do this:

yum install mysql mysql-devel mysql-server

The MySQL init script on CentOS might cause problems when you try to restart MySQL. In some cases it tries to start MySQL before the old MySQL process has stopped which leads to a failure. The solution is to edit the restart section of /etc/init.d/mysqld and add a few seconds delay between the stop and the start of MySQL.

Edit /etc/init.d/mysqld:

vi /etc/init.d/mysqld

and change this section:

restart(){
    stop
    start
}

so that it looks like this:

restart(){
    stop
        sleep 3
    start
}

This adds a three second delay between the stop and start of MySQL.

Then we create the system startup links for MySQL (so that MySQL starts automatically whenever the system boots) and start the MySQL server:

chkconfig --levels 235 mysqld on
/etc/init.d/mysqld start

Now check that networking is enabled. Run

netstat -tap

It should show a line like this:

tcp        0      0 *:mysql                     *:*                         LISTEN      2995/mysqld

If it does not, edit /etc/my.cnf and comment out the option skip-networking:

vi /etc/my.cnf

#skip-networking

and restart your MySQL server:

/etc/init.d/mysqld restart

Run

mysqladmin -u root password yourrootsqlpassword
mysqladmin -h server1.example.com -u root password yourrootsqlpassword

to set a password for the user root (otherwise anybody can access your MySQL database!).