Okay, so I can't fully answer this issue but I'll share what I've found out:
- Yes. Unfortunately Time Machine has deleted these, so anything unique that was in the past backups is gone for good.
- The contents of
.RecoverySets are copies of your Recovery HD. Ordinarily Time Machine shouldn't have more than one of these but, like you, I found the folder contained nearly a thousand identical sets. My best guess is that there is something wrong with my recovery partition that is causing Time Machine to think it has been changed, but that doesn't explain why Time Machine is creating so many copies without discarding any. I've filed a bug report with Apple, and I suggest anyone who encounters the same error does the same.
- You can workaround this issue with a bit of light Terminal work:
- First type
cd /Volumes/{Time Machine Backup}/Backups.backupdb, replacing the part in brackets with the name of your backup volume before hitting return.
- Next type
sudo rm -fr .RecoverySets and hit return, you'll be asked for your password so that the command can delete your existing recovery sets.
- Now run a Time Machine backup as normal using the menubar menu or by entering
tmutil startbackup in Terminal and hitting return again. Wait till the backup is finished, as this will recreate your .RecoverySets folder.
- Now type
sudo chflags simmutable .RecoverySets and hit return, entering your password again if prompted. This will lock the folder (though it may not show this in the Finder), preventing Time Machine from creating any duplicate recovery sets in future.
The above workaround has a few caveats; firstly you won't gain any new recovery sets, but that's unlikely to be an issue, but if you're worried your set may be outdated you can unlock the folder using sudo chflags nosimmutable .RecoverySets (after cd'ing to your backup volume), delete your recovery sets, run a Time Machine backup, then re-lock it again.
You may also notice errors in your console to the effect of "Could not backup OS X Recovery to…", but that's to be expected as you locked the target folder, it just means this workaround is doing the trick, so you can safely ignore these.
One further note; after deleting your .RecoverySets folder, you may not immediately see any extra free space in the Finder. The easiest way to do so is to open /Applications/Utilities/Disk Utility.app, unmount your backup volume and then mount it again, and you should see the correct free-space value, or you can just ignore it, as the free space should be there. In my case I freed up a massive 750gb by deleting my recovery sets folder, as I had over a thousand completely identical copies of my recovery partition in there (no wonder I only had 483kb of free space left!).
You may also want to investigate methods of repairing your recovery partition, but I'm not certain of the best way to do this; it couldn't hurt to at least try Disk Utility's first aid repair command.
I tried deleting the folder and the system was fine after that. The file wasn't created by the PopcornTime app for Mac but the iOSInstaller of PopcornTime. I tried to install the app on my iPad and the installer created that folder and all those large files.
So to answer the question: YES you can delete that folder and all the files inside it.
Best Answer
It's the folder where iTunes saves the backUps of your iDevice. And it takes so much space because each time you sync a device, previous backUps are not deleted.
Deleting the folder will, then, mean losing those backUps. Doing this regularly is advised for saving HD space. Just make sure to make a new backUp afterwards, and that you won't need those backUps.
You can do that through iTunes too, by:
Note that all of the backUps of that iDevice will be deleted.