Hello forum users, I have a problem that looks like this: I had devided my Toshiba drive into 2 partitions: Macintosh HD (HDD1) and Macintosh HD2 (HDD2) about 160 GB each. Had El Capitano on HDD1 - about 24 GB available and only pictures, videos, files on HDD2 - 40 GB available Sierra came out, I downloaded, not enough space on HDD1, so I installed on HDD2. However not a sing app installed on HDD1 under El Capitano, would run under Sierra (hdd2) now. So I erased the entire HDD2 - by Disk Utility and Terminal. I hoped, drives would merge into one with a total of 320GB - which of course not happened. This is the outcome of my operations: Macintosh HD (HDD1) 159 GB - of which 24 free Free Space 160 GB - completely invisible space Any ideas how to recover the missing 160 GB and merge it with to HDD1?