On my server, the root partition is 73GB, but the disk says, it is full, although there are only about 6GB used on that device:
# df -h Filesystem Size Used Avail Use% Mounted on udev 997M 0 997M 0% /dev tmpfs 202M 41M 162M 20% /run /dev/mapper/p22server-root 73G 68G 655M 100% /
(I use LVM on the server:
/dev/mapper/p22server-root -> ../dm-0)
If I check with
ncdu -x /
I find out that the total usage is just 5.9GB.
My guess is, that there must be files still open, that are not visible in the file-tree.
How can I debug this? I guess, that a reboot will restore the lost space, but rebooting is not possible right now.