I have a 500GB ext3 volume which under df is saying is 20% used (94GB), yet when I do du, it only shows some dozens of KB. This volume is used as a working volume for our backups (Amanda) but should have basically 0 usage when there is nothing running.

[root@windsor holding]# df -h /holding
Filesystem Size Used Avail Use% Mounted on
/dev/sdc1 504G 94G 385G 20% /holding
[root@windsor holding]# du -sh /holding
36K /holding


What gives, where's my space?

TIA,
Dominic

Fyi: This is Fedora Core 3 running Linux 2.6.9-1.667smp i686

By default when an ext2/3 filesystem is created 5% (25GB in your case) is reserved for root use. This is supposed to reduce fragmentation as well as allow root to log in case the filesystem becomes full. Since this is a data partition you can safely reduce this to zero. Reserved space does not show up as being used which is why the numbers from the output of df do not add up. You can change the amount of reserved space via the tune2fs command.

Now what is using 94 GB is a more difficult question to answer. Could be hidden files try:
du -hax

I think something was terribly wrong with that volume. I started fsck on it and it said fs contains errors, check forced, and it's been running for an hour doing nothing. It's an empty volume so even 500G shouldn't take very long, right?

Anyhow, I'm going to leave it fscking overnight and if it's still doing nothing tomorrow, like I said, it's only 36KB of data so I'll just pull that off and wipe the file system.

Geepers, I wonder what it is?