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we have file in Linux and copied to AIX. same file smaller size in AIX.

Linux - ext3 file system AIX - jfs2 file system

both file systems in same block size 4k

size in Linux
     du -sk
Size in AIX    
      du -sk

Any idea why its different

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No copy problem? If you copy the file back (to a different name) then it "becomes larger" again? Or have you checked hash values? – Hauke Laging Mar 2 '13 at 1:59
Agree with @HaukeLaging - check to see if the files' md5s match. – EEAA Mar 2 '13 at 2:00
How did you copy it? – Dennis Kaarsemaker Mar 2 '13 at 2:07
I use scp to copy the file, we notied this on multiple file. if I copy it back its bigger in linux – sfgroups Mar 2 '13 at 16:38
up vote 2 down vote accepted

Citing from my du(1) manual here (Fedora 18, coreutils-8.17-8.fc18):

du - estimate file space usage

There is a flag --apparent-size, that prints out (an approximation to) the space usage by the file, excluding extra space that the filesystem uses.

So, du estimates the space on disk used by the file, i.e., data blocks and metadata. AIX and Linux presumably are using different filesystems, the space used by metadata doesn't have to be the same.

Compare the output of ls -l for both files, that gives the length of the file itself.

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stat and istat give same size Length. linux Size: 1187252238, AIX 1187252238 bytes Thanks – sfgroups Mar 2 '13 at 16:42
OK, mistery solved then. – vonbrand Mar 2 '13 at 20:06

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