[CentOS] Disk usage for small files in ext3 in CentOS 5

Wed Mar 11 21:51:19 UTC 2009
Nicolas Thierry-Mieg <Nicolas.Thierry-Mieg at imag.fr>

Filipe Brandenburger wrote:
> Hello,
> I noticed something unusual today.
> If I "du" a small file (couple of bytes) in CentOS 5, it tells me the
> file is using 8kb, while I was expecting 4kb which is the block size
> I'm using.
> I tried this on several CentOS 5 machines, both x86_64 and i386:
> $ echo test >test.txt
> $ ls -l test.txt
> -rw-rw-r-- 1 filbranden filbranden 5 Mar 11 17:24 test.txt
> $ du -h test.txt
> 8.0K	test.txt
> I could not find any differences that would explain the behaviour.
> Have you seen this before? Can you reproduce it on your systems? Do
> you know how to get the CentOS 4 behaviour?

I don't reproduce on an x86_64 centos 5 machine:
[nthierry at localhost ~]$ echo test >test.txt
[nthierry at localhost ~]$ ls -l test.txt
-rw-rw-r-- 1 nthierry nthierry 5 Mar 11 22:44 test.txt
[nthierry at localhost ~]$ du -h test.txt
4.0K    test.txt

I'm pretty sure I did nothing special when making the fs.