rsync strange behaviour

[pagani laurent]

Hi,

I use the Macports rsync to make a carbon copy of my internal drive onto an external one.

I find that the external one takes more room than the internal one : 470 Gb against 455 Gb.
Both drives are declared in the Mac OS extended Journalized (whatever it is called in English). The external is HD, internall SSD.
Looking in detail at the files, I find that the /Users is using the same size almost : 347 and 348 Gb (no yet rsynced today), but
the /Applications use 22 Gb internal and 27 Gb external, e.g. /Library use the same 6.8 Gb, etc… So some directories occupy the same volumes, others don’t.
In particular, I found that Xcode is 7.8 Gb internal and 12 Gb external, among which Xcode.app/Contents/Developper was the main difference (7.1 and 11 Gb) but other dirs are either identical or twice the same size : Frameworks are 58 and 128 Mb, Resources are 109 and 111 Mb.
To be sure, I erased the Xcode.app/Contents/Developper in my external disk and launched rsync which rebuilt it back to 12 Gb of space!

So it is not a question of granularity I would say but why rsync is making some files bigger when copied outside ? I don’t think it is a bug so no track ticket but if someone knows the explanation, I am eager to hear it.

Thanks,
L.

"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème" (devise Shadok)