Complex sentence: Originally, LXC containers were not as secure as other OS-level virtualization solutions such as OpenVZ: in Linux kernels before 3.8, the root user of the guest system could run arbitrary code on the host system with root privileges, much like chroot jails.
Split into simpler sentences: Originally, LXC containers were not as secure as other OS-level virtualization solutions such as OpenVZ. In Linux kernels before 3.8, the root user of the guest system could run arbitrary code on the host system with root privileges, much like chroot jails.