du shows wrong size [SOLVED]

[huuan]

windows failed to extract a gz image of an ubuntu server dis that I have to install on another server so I uploaded the gz image file to our gentoo server to extract it there.
It started off as a 200 meg file but when extracted showed as aroun 1.4G.

ls -rlt
...
-rw-r--r-- 1 peon peon 4091904 Apr 7 06:17 lucid-server-uec-amd64-vmlinuz-virtual
-rw-r--r-- 1 peon peon 1476395008 Apr 7 06:17 lucid-server-uec-amd64.img
-rw-r--r-- 1 jonny wheel 200558263 Apr 13 12:05 ubuntu-10.04-beta2-server-uec-amd64.tar.gz

but when I do du

# du -hs /home/jonny/
842M /home/jonny/
# du -hs /home/
842M /home/
# du -hs /home/jonny/lucid-server-uec-amd64-vmlinuz-virtual
4.0M /home/jonny/lucid-server-uec-amd64-vmlinuz-virtual
# du -hs /home/jonny/lucid-server-uec-amd64.img
592M /home/jonny/lucid-server-uec-amd64.img


My question is: why does a file that shows listed as 1476395008 bytes show via disk usage as 592M
and for a runner up question how come after I extracted it as root it is owned by another user 'peon'

I think I am losing my marbles here... any insight?

Thanks,
Jonny

p.s.
# cat /proc/version
Linux version 2.6.23-hardened-r7 (root@as.ucsd.edu) (gcc version 3.4.6 (Gentoo Hardened 3.4.6-r2, ssp-3.4.6-1.0, pie-8.7.10)) #3 SMP Thu Mar 27 16:43:33 PDT 2008

<sheepish>I know it's a bit out of date, I will be upgrading over summer but meanwhile...

[platojones]

It's looks like a binary image file. It probably has a file system hole. See the last paragraph:

http://en.wikipedia.org/wiki/Sparse_file

Also known as a sparse file.

[Sadako]

The un-gzip'd archive could be a sparse file, ie have some large sequences of zero, the space for which is not actually allocated, therefore du will only show the amount of disk space it's actually using.

Try passing --apparent-size to du, see what size it tells you it is then.

Also, just out of curiosity, what does `file lucid-server-uec-amd64.img` return?

edit: I'm a slowpoke...
_________________
"You have to invite me in"

[dwbowyer]

sound like someone used "dd" to make a disk image, which as it happens makes an EXACT copy of a partition.... including any empty space.

[huuan]