I have a MacBook Air with 128GB SSD. I was shocked to find that it is full. I found that QuickBooks backups were taking 40 gigs because I had it backing up everyday and the backups include attachments. These are not incremental backups, so they are just copies of the same thing. So that was easy to get rid of those files and open up 40 gigs of space. But what I found were 20+ gigs inside of the hidden private / var folder. I tried rebooting but that didn't help. What I found were QuickBooks backups inside of one of the folders inside of the var folder. I tried deleting them, but the Trash wouldn't empty because it said they were being used (QuickBooks wasn't even running). So am I stuck with that space being wasted?