I'm trying to significantly reduce what is stored on my MacBook Pro as I'd like to replace the 1TB hybrid drive with a 500GB SSD.
At the moment, in About This Mac, the storage tab suggests that I have 220GB of storage occupied by 'System'. Can anyone tell me what this stuff is? The OS would be closer to 20GB, so I've no idea what all this is or how I can reduce it. Can anyone help?
Could be some giant cache file, email database, out of control log file.
I'd just show hidden files. Open your drive. Then Command-i the folders (get info). When you find a giant folder. Open it and do the same for its sub-folders until you find the culprit. When there are a lot of folders. I'll Get Info for groups to quickly isolate the folder. Alternatively you can display folder sizes in list view. Just be patient for sizes to populate.