File Size Depends on Where Stored ! ? !

[MWE]

I am running MSProject2000 under WinXP. I had a mpp file, A.mpp, that had
some things I wanted in a new file, B.mpp. I opened A.mpp, stripped out 90%
of its content, all of its macros, etc., and stored it as B.mpp Strangely,
B.mpp was the same size (~ 1.9mB) as A.mpp I tried the standard things for
mpp file bloat (immediate Save/As, Save AS .mpd, etc) but found that B.mpp
stayed at ~1.9 mB Actually the store at B.mpd did not work -- I could not
recover the original content from B.mpd

I then mistakenly did a Save/As B.mpp in a different directory than the one
in which it resided when I opened it. And, you guessed it, the file size
dropped to 350K which is about right. I am able to replicate this phenomena.
My conclusion is that when I tried to resave it in the original directory
immediately after opening it, MSProject thought "well, nothing has changed,
so I will just tweak the date and time saved and move on."

It gets even better: So I tried the process of saving in a different
directory on several other mpp files and they all dropped in size by 50%

Any thoughts on what is happening here?

Thanks

 

[JackD]

Different block size on the hard disk can cause this. Larger disks have
larger blocks, thus the minimum size of a file is larger.
There might also be compression enabled on the other disk.

 

[MWE]

Jack: all file saving was to the same drive and actually to the same
directory down the first few levels. Only the final subdirectories were
different:
D:\abc\def\hij\Dir1
D:\abc\def\hij\Dir2
There is no file compression and the file size on both Dir1 and Dir2 varies
from 15kB to 20mB.

Also:
1. this phenomena occurs on all mpp files on all drives
2. the phenomena even occurs when I copy, say A.mpp from Dir1 to Dir2 and
then save it back to Dir1

Any other thoughts?

***************************************

 

[JackD]

Are you saving or copying? It is not clear.

 

[MWE]

The file size reduction phenomena occurs when an mpp file is saved in a
directory other than the one in which it was opened. I have tried this on
multip mpp files on different drives and it works. In the most blatent test
I did the following:
1. A.mpp was in Dir1
2. I copied A.mpp from Dir1 to Dir2
3. I renamed A.mpp in Dir1 to A1.mpp
4. I opened A.mpp in Dir2 and then immediately saved it into Dir1
5. I compared the size of A1.mpp and A.mpp (both in Dir1)
6. A.mpp was half the size of A1.mpp

I believe that the process of saving an mpp file into a new directory
envokes some sort of file "clean-up" that eliminates the crap that has been
building up over time. Sort of like the .pst file compression one can do in
Outlook

If I repeat the process outlined above on the same file, there is no
reduction in file size the 2nd time.

Any further thoughts?


*******************************

 

[JackD]

No thoughts. An interesting phenomenon though.