My linux server reports high disk space usage for device /dev/sda4 mounted on / as shown below: [root@stormtrooper03 /]# df -hFilesystem      Size  Used Avail Use% Mounted on/dev/sda4       126G  114G  5.5G  96% /tmpfs            32G     0   32G   0% /dev/shm/dev/sda2       239M  118M  109M  53% /boot/dev/sda1       150M  264K  150M   1% /boot/efi/dev/sda5        63G   52M   60G   1% /home/dev/sda6        63G   54M   60G   1% /tmp/dev/sda7        63G  2.6G   58G   5% /usr/dev/sda3       539G   11G  501G   3% /var/dev/sdb1       917G  857G   51G  95% /data/1/dev/sdc1       917G  861G   47G  95% /data/2/dev/sdd1       917G  282G  627G  31% /data/3/dev/sde1       917G  861G   47G  95% /data/4/dev/sdf1       917G  858G   50G  95% /data/5However, I know there is much less than this amount used by running du -sh /* as shown below. I need to clean files setting on this device but I can't find them!![root@stormtrooper03 /]# du -sh /*6.7M    /bin116M    /boot3.7T    /data356K    /dev30M /etc172K    /home638M    /lib20M /lib6416K /lost+found4.0K    /media4.0K    /mnt3.8G    /opt0   /proc42M /root9.2M    /sbin4.0K    /selinux4.0K    /srv0   /sys2.1M    /tmp2.5G    /usr11G /varUpdateI have found reason for this: a new disk was mounted on /data/3 which had 110GB of data and became hidden from the filesystem after mounting a disk on it.The answer to the question why does mount happen over an existing directory explains how to uncover original data using mount --bind but it doesn't explain how to find if your system has such shadowed directories if you don't know ahead of time. Is there a quick way to a list of disks mounted on non-empty directories without checking each one individually by mount --bind?
How to list all disks mounted on non-empty directories (shadowed directories)?
disk usage