【systemd】押すなよ! 絶対に押すなよ!!

起動禁止設定

# systemctl mask named
# systemctl unmask named-chroot

起動しようとするとエラーになる

# systemctl start named
Failed to start named.service: Unit is masked.

# echo $?
1
  mask NAME...
        Mask one or more unit files, as specified on the command line. This will link these units to /dev/null, making it impossible to start them. This is a
        stronger version of disable, since it prohibits all kinds of activation of the unit, including enablement and manual activation. Use this option with care.
        This honors the --runtime option to only mask temporarily until the next reboot of the system. The --now option can be used to ensure that the units are
        also stopped.
  
    unmask NAME...
        Unmask one or more unit files, as specified on the command line. This will undo the effect of mask.

CentOS 7.0 – man page for systemctl (centos section 1) – Unix & Linux Commands