Hello,
We had some issues reported by clients before with snapshots creation on Vmware machines. The investigation leads to disabling cPanel's securetmp feature.
To disable it just run
# touch /var/cpanel/version/securetmp_disabled
and then remove /tmp entry from /etc/fstab and reboot server.
This was not specific to CloudLinux systems. CentOS cPanel servers had this problem as well.