Empty /etc/fstab after cpanel installation on Centos 7 container under proxmox

Dear All, I have installed cpanel under proxmox container where CentOS 7 is installed on virtual machine. After installation I have enabled quota from WHM also tried from command line but, I have found empty /etc/fstab after all. Quota's are not being enabled, can someone help on this :- Just to add some more information that I have Filesystem Size Used Avail Use% Mounted on /dev/loop0 590G 52G 509G 10% / none 492K 0 492K 0% /dev udev 32G 0 32G 0% /dev/tty tmpfs 32G 0 32G 0% /dev/shm tmpfs 32G 17M 32G 1% /run tmpfs 32G 0 32G 0% /sys/fs/cgroup here is my mount command output :- [root@srv ~]# mount /var/lib/vz/images/900/vm-900-disk-0.raw on / type ext4 (rw,relatime) none on /dev type tmpfs (rw,relatime,size=492k,mode=755,uid=100000,gid=100000) proc on /proc type proc (rw,nosuid,nodev,noexec,relatime) proc on /proc/sys/net type proc (rw,nosuid,nodev,noexec,relatime) proc on /proc/sys type proc (ro,nosuid,nodev,noexec,relatime) proc on /proc/sysrq-trigger type proc (ro,nosuid,nodev,noexec,relatime) sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime) sysfs on /sys type sysfs (ro,nosuid,nodev,noexec,relatime) sysfs on /sys/devices/virtual/net type sysfs (rw,relatime) sysfs on /sys/devices/virtual/net type sysfs (rw,nosuid,nodev,noexec,relatime) fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime) lxcfs on /proc/cpuinfo type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/diskstats type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/loadavg type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/meminfo type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/stat type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/swaps type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /proc/uptime type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) lxcfs on /sys/devices/system/cpu/online type fuse.lxcfs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) udev on /dev/full type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) udev on /dev/null type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) udev on /dev/random type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) udev on /dev/tty type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) udev on /dev/urandom type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) udev on /dev/zero type devtmpfs (rw,nosuid,relatime,size=32853420k,nr_inodes=8213355,mode=755) devpts on /dev/console type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000) devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=100005,mode=620,ptmxmode=666,max=1024) devpts on /dev/ptmx type devpts (rw,nosuid,noexec,relatime,gid=100005,mode=620,ptmxmode=666,max=1024) devpts on /dev/tty1 type devpts (rw,nosuid,noexec,relatime,gid=100005,mode=620,ptmxmode=666,max=1024) devpts on /dev/tty2 type devpts (rw,nosuid,noexec,relatime,gid=100005,mode=620,ptmxmode=666,max=1024) tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,uid=100000,gid=100000) tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755,uid=100000,gid=100000) tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755,uid=100000,gid=100000) cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd) cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb) cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices) cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio) cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio) cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event) cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset) cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct) cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer) cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory) cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids) cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma) mqueue on /dev/mqueue type mqueue (rw,relatime) anyone please advise Thank you