df gets different result from du?

liyuefu · 09-29-2005, 08:46 PM

I got a strang problem.

I have a partion /u01, when I check its space, the result of
df and du is different.

[root@spp-db3 u01]# du -sh /u01
4.5G /u01
[root@spp-db3 u01]# df -h /u01
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 20G 9.2G 9.1G 51% /u01
[root@spp-db3 u01]#

df says I have used 9.2G, and 9.1G left, and du says it is only used 4.5G.
I can't find which file occupies the space 9.2G - 4.5G = 4.7G.

thanks a lot.

Talavis · 10-01-2005, 02:13 AM

Did you use du as root? If I'm not wrong, du will skip archives it has no permissions to, while df still counts them.

liyuefu · 10-01-2005, 09:44 AM

I know there maybe some difference between df and du , but I don't think
the difference is so big, it's about 4G.

the directory is /u01, which is used by oracle.
Maybe it's because of oracle?

hondo · 10-01-2005, 10:08 AM

I think the df command checks how much disk space is avalible and used on one partition and the du command can check files, directories and other. I have serveral file systems in one partition and when i specified for example /home which is one of them, i got the size of the partition which not only is used for the /home directory. I used the df command.

slackhack · 10-01-2005, 10:45 AM

yeah, df shows the amount of space left on the entire filesystem. man df