ZFS vs EXT3 file/folder sizes

[Oko]

I am migrating files using rsync from an old CentOS 4.8 (I think uses EXT3) to FreeNAS 9.1.5 box. I run rsync in "pull mode" on FreeNAS box and rsync server on CentOS 4.8. I noticed significant differences in the file sizes (FreeNAS being much smaller) when I run

Code:

du

command. Since I knew I had a lots of sparse files I used special option in rsync to transfer those. I am sure there was lots of fragmentation on the old CentOS server and lots of garbage dotfiles created by programs which I didn't transfer but that still doesn't explain such a huge difference.

Are data sets compressed on FreeNAS using lzma compression? Is that why I see such smaller files running

Code:

du

on FreeNAS? Essentially I moved 1.5 TB of data to little over 1TB of space.

 

[solarisguy]

Storage page in the GUI tells you both whether you have compression and how well files had been compressed.

If you do not trust GUI ;)

Code:

zfs get compression,compressratio

might give similar results

 

[cyberjock]

du and df do NOT reflect reality for ZFS and therefore should never be used or trusted except for very anecdotal purposes.