New iMovie 10 Library conversion

[mzd]

My old iMac, which had an older version of iMovie, died recently. I got a new iMac which came with iMovie 10. I hadn't updated the old one since the reviews for iMovie 10 were not so favorable. I don't do a ton of video editing, btw. Anyway, welcome to iMovie 10. The first thing it does is convert all the old projects. It supposedly keeps the old versions for backwards compatibility. Apple says you can delete those old folders.
Here is where I am confused. Some of my old videos/projects were stored on a 1TB external drive. My old iMovie Events folder shows 609.66 GB. The new iMovie Library created on that drive is 604.1 GB. Unless I am missing something, those two folders alone exceed my 1TB drive capacity, let alone the 234.42GB Lightroom Photo library that also resides on that same 1TB external drive, along with some other folders in the multi-GB range.
I wanted to pull the old iMovie Events folder off that drive so I wasn't storing duplicate files on my main external drive, but I am wondering a) will removing it affect the new iMovie Library package that should contain all the old event files, and b) how much space is it really using since it is impossible to store of 1500GB of data on a 1TB drive as is currently reported.

 

[ApfelKuchen]

I don't know if they handled it the same way for iMovie Library conversions as they did for Photos/iPhoto, but the numbers suggest they do. This is how it works for Photos/iPhoto:

The new library doesn't have copies of the original files from the old library, it contains "hard links" - both libraries contain links to the same original file (the same file appears in both libraries). If you delete the old library, the image files remain on the hard drive, as they're still hard-linked to the new library (the existence of the remaining hard link prevents the files from being deleted). You have to delete both libraries in order for the original image files to be deleted (deleting both libraries deletes both hard links).

The confusion comes from how Finder reports the size of those libraries - the original files are being counted twice - once as a part of the old library, and again as part of the new library, even though there's just one physical copy of each file.

 

[mzd]

thanks, that makes sense. i was checking if the files in either folder where aliases, but they weren't. if i look at Storage under About This Mac, it shows videos taking up approx 620GB. this further supports the notion that there is only one copy of video files on the drive.