1. Stop cpanel, apache (litespeed), mysql services:

    /etc/init.d/cpanel stop
    /etc/init.d/httpd stop
    /etc/init.d/lsws stop
    /etc/init.d/mysql stop

    2. Umount /tmp and /var/tmp:

    umount -l /tmp
    umount -l /var/tmp

    3. Move /usr/tmpDSK file to another location (just in case you’ll need to mount it somewhere else to preserve data):

    mv /usr/tmpDSK /usr/tmpDSK_back

    4. Modify /scripts/securetmp to set tmpdsksize to desired size:

    vi /scripts/securetmp

     

    $tmpdsksize = 2048000

    5. Run:

    /scripts/securetmp

    6. Start cpanel, apache (litespeed), mysql services:

    /etc/init.d/cpanel start
    /etc/init.d/httpd start
    /etc/init.d/lsws start
    /etc/init.d/mysql start

Increase tmp partition size in cPanel and secure it