I am being pushed to upgrade my current MacOS: 10.10.5 Yosemite, mid-2015 MBP, 16GB memory, Parallels 13. I can't get El Cap any more -- Mac store wants to push High Sierra and nothing else. Before I jump in to HS, I wanted to test out some of the app I have on this machine, and a Parallels VM seems the best way to do it. There seem to be two approaches: (1) brand new guest Mac VM into which I install HS; and (2) clone my existing Yosemite and run the upgrade installer. I tried approach (1) using some detailed instructions that basically call for starting the upgrade installer, bailing out at the appropriate time, capturing the install app on the HD, and running it in the new VM. That failed with an error message regarding invalid image. I am thinking about approach (2) since that will probably be the eventual path anyway. Is it possible to virtualise an existing running OS and create a virtual guest OS from it? Thanks for any help and any guidance on either of these approaches.
If you have downloaded El Capitan from the Appstore you will find it in your purchased app listing. Every OS is inside there if you need it. However it´s a good practise to keep a copy on your dropbox or any preferred disk.
