why the used-space of "df -h" is larger than the result of "du -hs /"?

Question

the result of "df -h" shows below:

/dev/sda1       5.6G  3.2G  2.2G   60% /
udev            992M  4.0K  992M    1% /dev
tmpfs           401M  752K  401M    1% /run
none            5.0M     0  5.0M    0% /run/lock
none           1002M     0 1002M    0% /run/shm

the result of "du -hs /" shows below:

1.7G    /

Why is that?

Is that the full output of du -hs /? When I run it on my computer, I do not have permissions to read many directories. — Sparhawk, Jun 01 '13 at 03:37
Perhaps this possible dupe? http://askubuntu.com/a/79996/53508 — Sparhawk, Jun 01 '13 at 04:07
I am afraid not. That command is to reduce the reverse space of system. but the reverse space is not large to 3.2-1.7=1.5G — Emiya Kiritsugu, Jun 01 '13 at 04:21
Oh yes, sorry, I misread the other question. Also, there the df used space ≈ du output. — Sparhawk, Jun 01 '13 at 04:24
Another possible dupe? http://askubuntu.com/questions/209934/why-do-df-and-du-show-different-output — Sparhawk, Jun 01 '13 at 04:26
Hm, not sure, then, sorry. Hopefully someone else can help you. — Sparhawk, Jun 01 '13 at 05:30

score 0 · Answer 1 · answered Sep 11 '13 at 02:24

df and du measure two different things....

du reports the space used by files and folders--even this is more than the file size. A few quick experiments on my system show that 4K is a minimum file size in terms of disk space.

df reports the space used by the file system. This includes the overhead for journals and inode tables and such.

http://www.linuxquestions.org/questions/linux-general-1/du-vs-df-huge-difference%3B-disk-space-vanishing-539185/#post2678197

why the used-space of "df -h" is larger than the result of "du -hs /"?

1 Answers1