Huge Folder size discrepancy between 10.1 Managed and 10.0.9

I sure do Hope that someone can help me out with this.
I don't want to make any mistakes that would result in Data loss.

I have all my media for a large project I am working on on a Drobo 5D.
The Drobo has a total Max usable space of 16TB. (5 Drives each 4TB in size)

When FCPX 10.1 came out I upgraded and "saved" my old library. (Just in case)
Once the "upgrade" was complete there were two different directories on my DROBO there was:

"DROBO Old Final Cut Projects and Events" (which has a "normal" folder structure) &
"DROBO Final Cut Projects and Events" (which had the "contained / managed structure)

Shortly after I "upgraded" something happened and all my subtitles (all of the footage was subtitled... all 300 hrs) disappeared...
After about 3 hrs of freaking out I quickly discovered that the subs and all my old project files were still ok in the old (just in case) directory and all I needed to do to keep working was go back to use 10.0.9 which is what I have been doing.

However Now I have very little space on my DROBO and I want to get rid of the "newer" and unused "DROBO Final Cut Projects and Events" folder (which now shows up as a normal folder / directory as I no longer have 10.1 installed)

And here comes the QUESTION:
The numbers don't add up.... the new Folder (the one I want to DELETE for 10.1) claims a size of 8.06TB (on "10.1 FCP P&E")
and the old folder that I want to SAVE claims a Size of 10.79TB (on "old FCP P&E").
In addition to those folders I have an additional 3.5TB of other files outside of those directories...

OK so it doesn't take a rocket scientist to see that the "used" space on my Drobo according to my finder is 22.35TB which is already impossibly large as I simply do not have that space on the drive... So when I look into the new directory (the one I want to delete) all the files appear to be "real" and not aliases which was the first thing I thought may be the issue (something funny where it was counting the file twice...)

Anyway I just really want to DELETE that "new 10.1" directory however not at the cost of messing up my perfectly good 10.0.9 workflow.
Please advise.
thanks!


Final Cut Pro X, OS X Mountain Lion (10.8.5)
terraform

Hi Shawn,

Do a Get Info on the Drobo drive to see how much space is really used. I think it will say 14.29TB. Is that correct?

- Ronny

Hi Ronny, thanks for your response.
actually it says 12.52TB
After some research it would appear this issue is due to Apples use of "Hard links" with it's library structures as opposed to Sym or alias links... however still have not figured out if it is "ok" to delete the files in the 10.1 bundled library... to be safe I am backing up the 11+TB now and then will delete the 10.1 bundle and see what happens...

fyi this is where I found the info on the "Hard Links"
www.rippletraining.com/fcpx-features.html
in Upgrading 2 vid (the second one)

and attached is a pic of my folders and my Drobo dash.

Yes, I already suspected hard links to be at the root of this.

It's a good idea to create a safety backup, but I'm quite sure you can safely delete the 10.1 Library folder without any issues.

The 10.1 Library folder is smaller than your original 10.0.9 folder because you seem to have lost all database links to your subtitles during the update process. I wonder why this has happened, we have updated quite a number of 10.0.9 projects with subtitles to 10.1 and we did not have this issue. Did the subtitles disappear as soon as the projects were updated or did something else happen?

- Ronny

Actually the subtitles disappeared after the first (point) update after 10.1 and to be honest I don't remember exactly what happened... I freaked out... then hooked up the drobo to my laptop which was still running 10.0.9 and saw that everything was still stable in 10.0.9 and never looked back (have not had free time to problem solve 300 hrs of missing subs)

Anyway I will finnish the Backup process this eve and delete the the 10.1 bundle and report back
thx!