vps unknown usage of disk space

Hello, [root@dns ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/cos-root 499G 494G 5.2G 99% / devtmpfs 2.9G 0 2.9G 0% /dev tmpfs 2.9G 0 2.9G 0% /dev/shm tmpfs 2.9G 8.7M 2.9G 1% /run tmpfs 2.9G 0 2.9G 0% /sys/fs/cgroup /dev/vda1 985M 202M 733M 22% /boot tmpfs 581M 0 581M 0% /run/user/0 tmpfs 581M 0 581M 0% /run/user/1002 [root@dns ~]# du -h --max-depth=1 /home 0 /home/cPanelInstall 1.1M /home/.cpcpan 69G /home/virtfs 168M /home/cpanelsolr 16K /home/clamav 47G /home/username 116G /home [root@dns ~]# du -h --max-depth=1 / 231M /boot 0 /dev du: cannot access "/proc/7647/task/7647/fd/4": No such file or directory du: cannot access "/proc/7647/task/7647/fdinfo/4": No such file or directory du: cannot access "/proc/7647/fd/4": No such file or directory du: cannot access "/proc/7647/fdinfo/4": No such file or directory du: cannot access "/proc/7710": No such file or directory du: cannot access "/proc/7711": No such file or directory du: cannot access "/proc/7714": No such file or directory du: cannot access "/proc/7715": No such file or directory 0 /proc 8.4M /run 0 /sys 1.3G /etc 16M /root 11G /var 196K /tmp 11G /usr 47G /home 0 /media 0 /mnt 165M /opt 0 /srv 0 /backup 70G / i am unable to find more than 250 gb where it is being used some time before i faced similar issue and that mysql error file grew to about 450 gb but now mysql error file size is normal, even i deleted and recreated that file. and unable to findout where space is being used