>My question is why is Retrospect incorrectly reporting/calculating 
>the space requirement of the data during the restore process? It 
>appeared to correctly calculate the amount of data (~840MB) when I 
>did a test backup of the newly restored partition.

It does sound like Retrospect is being too conservative in guessing 
how much room the restored files will require. I am not sure how 
Retrospect can tell ahead of time how much room the files will 
actually take up on disk, so it may not be easy to avoid the problem, 
but it would be nice!

The cause of the problem is that the amount of data in the file, and 
the size of the file on disk, are two different things. You can 
easily confirm this by creating a file which is one character long in 
some editor, and then checking the file size. The bigger the disk, 
the bigger the granularity in the file sizes. In simple terms the 
file system typically just divides the disk up into N little pieces. 
N is fixed, so the bigger the disk, the bigger the pieces.

When Retrospect backs up the data, it only needs to record the actual 
data, the original file "size" is not relevant since you may restore 
the file into a different sized disk.

More recent file systems reduce the granularity, since they are 
designed to cope with bigger disks and more files. On the Mac, MacOS 
Extended (aka HFS+) is better than MacOS Standard (aka HFS) for large 
disks. On Windows I am a bit vague on the details, but think there 
are similar advantages for FAT32 over FAT16, but take that with a 
grain of salt.

John Gee                        [EMAIL PROTECTED]
Dunedin, New Zealand            Programmers live in interesting times...

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