[mikebore]

I just repeated this erase/copy run and immediately on completion used Whatsize to see where the main space is being used.

The top seven items on the source are:

1.98 Gb System
1.37 Gb Library
718 Mb Applications
547 Mb private
500 Mb usr
396 Mb Users
17.8 Mb mach_kernel

and on the copy are:

3.69 Gb System
2.16 Gb Library
1.11 Gb usr
1.06 Gb Applications
434 Mb private
396 Mb Users
75.4 Mb .Spotlight-V100

Total used on the source is 5.82 Gb, and on the copy is 9.13 Gb

All these are in Whatsize Gb not SL Gb.

Does this make any sense to you?

I have sent the log from this run from the application.

EDIT I meant to add that the spotlight file on the source is zero. It is not excluded from Spotlight by the privacy option.