I had a major calamity, my internal HD crashed. Rather than open the 27 inch mid 2011 imac I want use an external SSD as my start up disk. I lost all my original data including the High Sierra OS. How can I restore the OS to this new SSD?
iMac 27" 5K, macOS 10.14
Once you correct the formatting, you can try booting while holding Shift-Option-⌘-R. That should install the version of macOS that came with your computer or the closest one that's available. If that works and you don't end up with High Sierra, you will have to update afterwords.
Personally I've never tried installing the OS to an external drive from a Mac with a broken internal drive.
Try running Disk Utility on your external SSD format it as HFS+ (not APFS) with the GUID partition scheme. Then do a FirstAid. Then try the install again.
What brand SSD do you have (e.g. OWC, Crucial, etc.)?
Try Internet Recovery by restarting with the Command+Option+R keys pressed until you see a spinning globe. This will boot you to Apple's recovery servers and you should see a Utilities menu where you can reinstall High Sierra. When the install starts, choose to see additional disks and choose your external drive. During the OS install you can restore user data, apps, settings with Setup Assistant - if you have a back up - or bypass this step and just install the OS.
Just seen your second point it's a 2 TB Crucial Part no. confirmed verbally by crucial tech.
Just found HFS+ in google search & tried partition to mac os etxended case sensitive journaled but it made no difference
So if I go back to the original partition Mac OS Extended Journaled I will still have the problem that I have a missing firmware partition and my old HD has been corrupted so I cannot save anything from it. Am I between a rock and a hard place?
Thank you for responding. I followed your instructions but when I click on the SSD a window appears 'cannot install because computer is missing a firmware partition"
Any suggestions please
Sorry to be a pain.
I am partitioned currently as Mac OS extended journaled. HFS is not an option.
You do now want your Mac formatted as case-sensitive.
I think dialabrain meant...
You do not want your Mac formatted as case-sensitive.
I think you are correct. 😎
darn typos.
How do I restore High Sierra to a mid 2011 imac
