Nick_Macartney wrote:
Macbook pro os 26.1 I was copying from one external drive to another and suddnely noticed my hard drive almost full. About 300 GB have gone onto it. I cannot find anywhere the files that have suddenly moved onto the hard disk. I searched all files.
All Volumes within a Container share space without penalty—giving and taking as needed:
Trash
Time Machine local backups
Virtual memory
cache memory
tmp files
etc...
reboot the machine, do a Safeboot all effect what is presented in your "System Data"
What Apple used to label "Other" is now labeled "System Data".
Empty your Trash — Delete files and folders on Mac - Apple Support
Delete files and folders on Mac - Apple Support
How to free up storage space on your Mac - Apple Support
Free up storage space on your Mac - Apple Support
See used and available storage space on your Mac
See used and available storage space on your Mac - Apple Support
Try something like OmniDiskSweeper for a GUI to get a good look at itemized file size and location:
OmniDiskSweeper http://www.omnigroup.com/more