amount of data and differences is a big mystery

[pxmy]

i have a 300 gb mac

the finder reports that there is 100gb available

i've run a number of disk inventory utilities and they all come back with only @ 150gb used

i've also run disk utility (from the cd disk) and everything checks out ok

i have run a clone of the drive and the info reported is @ 200gb consistent with what finder reports

i have a time machine complete copy of the drive and it reports only @ 150gb

i have even taken my computer into the genius bar and talked to apple support and NO one has any answers or can even begin to explain why the numbers are different - any ideas?

[#1 Rhapsody]

The missing 50GB could be because of the HFS+ formating of the drive. The 300GB size is when the drive is unformatted. So you only have 100GB free and 150GB used.

[pxmy]

The problem just started. I've had the computer for over a year.

[Mikuro]

A 300GB HD is actually only 279GB in computer terms, and the usable space is even less due to formatting requirements. So just from that the discrepancy becomes a lot smaller.

It could be that you have some very large temporary system files, like virtual memory swap files, which some software would not copy or report. That could explain the rest of the discrepancy.

Take a look at your disk with OmniDiskSweeper and see if anything large catches your eye.

[pxmy]

That's part of the issue. I've run ODS and it only returns data up to the 150gb. What explains the difference between the clone size and TM size?

[fryke]

The problem has only just been _perceived_. GB ≠ GB.

[pxmy]

Sorry... not sure what that means.

[fryke]

I wrote the post earlier. It was meant to be above.
A "300 GB" harddrive actually contains 300'000'000 Bytes. So it contains 292'968.75 KB and 286.10 MB unformatted HD space. Formatted, it'll probably be a little less even. (Like has been said before.) Depending on which measurement you take for which task, you might be simply counting different things.

The Time Machine backup should be _bigger_ than the drive's contents in Disk Utility, though. But if 150 GB is actually used on the drive, ~100 GB free sounds _about_ right.