Discrepancy df/du

English Install/Boot/Login
#1

Howzit Folks?

I get the following results for various commands and can’t figure out what is causing the discrepancy:

df -h /
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 2.0G 2.0G 0 100% /

du -hx --max-depth=1 /
0 /proc
12K /mnt
20K /tmp
4.0K /opt
14M /sbin
0 /sys
14K /media
4.0K /selinux
4.0K /srv
4.0K /winsys
4.0K /var
4.0K /usr
4.0K /home
0 /dev
8.1M /bin
258M /lib
18M /lib64
44M /boot
16K /lost+found
24M /root
44M /etc
408M /

Can anyone tell me why there is a difference of 1640 MB between the 2 commands for the root partition?

Cheers
Bruce

#2

One reports the file actual size the other reports the sector byte usage whether or not the file takes up the full sector.

#3

Amounting to being out by a factor of 5…

?!

You could try the --apparent-size flag.

#4

Sure if a lot of files are just over the modulus of the basic block size you can have tons of wasted space.

#5

Is this on a running system? Is the condition persistent?

One possibility is that there is a file still being held open by a process, but which has been deleted. The blocks are still in use, but the file cannot be found by du. When the process exits the blocks are reclaimed.