OK, I can now definitively answer artie505's and keys' questions. So, here goes.
First, after my test yesterday about installing OS 10.11.4 on an Erased, Mac-formatted flash drive, I booted from that flash drive on my mid 2013 MacBook Air. As I previously stated, that worked fine. However, doing that, for some "strange/unknown"reason, caused a start up or restart of the machine to take longer than usual. So, I decided to take care of this issue by doing the following about 2 hours ago:
1. Copied the Main Identity Folder for Office 2011 to an empty, Mac-formatted flash drive (will show why below).
2. Copied the "Install OS X El Capitan" file I downloaded yesterday to the Flash Drive.
3. Re-started the MacBook Air from the SuperDuper! backup/clone I had made just this past Friday.
4. Copied the "Install OS X El Capitan" file from the flash drive to 1) the Applications folder on the SD backup, and 2) the Upgrades folder for OS 10.11 I have on the SD Clone.
5. Launched Disk Utility from the Applications folder on the SD clone, and Erased and Formatted the Macintosh SSD partition on the internal SSD of the MacBook Air.
6. Launched the "Install OS X El Capitan" file from the Applications folder (on the SD Clone), and did a clean installation of OS 10.11.4 from that file to the Macintosh SSD on the MacBook Air.
7. After that installation completed, I was then able to do the migration of needed stuff from the SD clone to the Macintosh SSD partition, without needing to re-boot the MacBook Air, from that partition.
8. Finally, I re-started the MacBook Air from its internal Macintosh SSD partition, and it worked perfectly! And, now my MacBook Air starts (and re-starts) like "normal", ie, not taking long at all.
9. I then copied the Main Identity file for Office 2011 from the flash drive to the appropriate directory location on the Macintosh SSD partition. The primary purpose for doing that was to insure that my EMails (on the Air) were up to date. I did not need to back up any other file onto the flash drive.
Now, a couple of comments, both "in general" and specifically for the 2 individuals mentioned above:
1. For some reason, when I tried to use Disk Utility to Erase the Samsung 251 gig SSD in the MacBook Air (ie, the "top" level, with the subsequent (visible) partitions Macintosh SSD and eDrive), it would not let me do that. So, I just erased and formatted the Macintosh SSD partition. In a way, that saved me time in the end, as I did not need to re-create TechTool Pro's eDrive at the end of the process.
I guess if one needs to first install a brand new drive/SSD inside their machine, and boot from the SD backup/clone, Disk Utility would most likely allow one to start the Erase and Format process at that top level.
2. For artie505: I had previously read, on NUMEROUS occasions, and on numerous sites, that after launching the "Install OS X El Capitan" file from the Applications folder, and after the installation completed, that file would be gone. But, in this case, it did not. I'm wondering if that situation occurs when doing the installation on the same drive, but on different partitions? I've never done that. When OS 10.12 arrives, I plan on launching its "Install OS X" file from a location on my SD backup/clone, and in fact, I'll first place it inside that clone's Application folder.
2. For keys: this process did create the Recovery HD partition, as expected.
Last edited by honestone; 05/16/16 06:55 PM.
