Are you by any chance using the new APFS, if so maybe do some googling and read up on automatic "Snapshots"Prior to updating to Mojave, I had 167 GB of free space, now I only have 69 GB. This thing is a blinkin' hog; I wish I would have kept Serria. And, I haven't added any new software. This is nuts!
Sorry for not being clearer...Great idea! I have a 2 GB external but what do you mean by HFS+? I'm not familiar with that.
Got it! I downloaded Carbon Copy Cloner so I see how things work out. Thanks much!Sorry for not being clearer...
Mac OS Extended or HFS+ is an improved version of Apple's Hierarchical File System from the mid-1980s.
The normal format in most cases today would be "Mac OS Extended (Journaled)".