Help with my crashed iMac

[GPO]

Hi Team, please could you advise me on getting my iMac late 2012 27 inch macOS Catalina working again. I had a problem which forced me to go back using Time machine but this failed on any of the previous backups and then the imac would boot up, I then booted with cmd and +R and tried to reload the the OS but I was unable to do because macOS HD and macOS HD-Data memory was nearly full, I wonder had the time machine filled the memory because my 3TB HDD still had 1.2TB spare memory.
I then connected a external portable HDD to the Mac and from recovery mode loaded macOS to it but it was Mojave not Catalina. This enabled me to boot up from the portable drive and then clear out some of the memory on macOS HD ,so I could then using recovery mode download macOS to my iMac. This worked but it was Mojave again, it boots up to password screen but upon entering my password the timer just spins forever. Is the problem that Catalina created macOS HD and HD-Data.

Any suggestions would be great, I would like to keep my data if possible as it looks like the time machine was not working correctly.

Many thanks
Gpo

 

[Fishrrman]

Are you still able to boot from the external drive?
Can you at least "get to the finder"?

It's hard to tell "where you are" right now...

If you can get to the finder...
And if you can "see" the internal drive on the desktop...

My advice would be:
a. get an external drive.
b. download CarbonCopyCloner (free to download and use for 30 days)
c. clone the INTERNAL drive to the external drive

Now you have an exact copy of the contents of the internal, which includes your personal data.

Next, I would boot to INTERNET RECOVERY (this IS NOT THE SAME as "the recovery partition).
Command-OPTION-R
at boot

Then I would open disk utility.
I would go to the view menu and choose "show all devices". VERY important step.

Next, I would ERASE the ENTIRE internal drive.
(you can't do this in the recovery partition).

Then I would re-install the OS.
I'd prefer Mojave, but you'll "get what they offer you".

Once the install was done, I'd see if setup assistant would bring over my personal data from the CCC cloned backup...

 

[GPO]

Are you still able to boot from the external drive?
Can you at least "get to the finder"?

It's hard to tell "where you are" right now...

If you can get to the finder...
And if you can "see" the internal drive on the desktop...

My advice would be:
a. get an external drive.
b. download CarbonCopyCloner (free to download and use for 30 days)
c. clone the INTERNAL drive to the external drive

Now you have an exact copy of the contents of the internal, which includes your personal data.

Next, I would boot to INTERNET RECOVERY (this IS NOT THE SAME as "the recovery partition).
Command-OPTION-R
at boot

Then I would open disk utility.
I would go to the view menu and choose "show all devices". VERY important step.

Next, I would ERASE the ENTIRE internal drive.
(you can't do this in the recovery partition).

Then I would re-install the OS.
I'd prefer Mojave, but you'll "get what they offer you".

Once the install was done, I'd see if setup assistant would bring over my personal data from the CCC cloned backup...

Hi Fishrrman,
Thanks for getting back to me, since my original post I have got my Mac running on Mojave although sometimes it freezes or I cannot shut it down. I think the trouble lies with the two volumes created when I upgraded to Catalina macOS HD and macOS HD-Data, both are nearly full and HD-Data has the same files as HD. Also I have run the First Aid disk utility on both volumes and HD-Data shows numerous Directory errors but no disc errors.
I think I need to go for a clean install, I will stick with Mojave, Catalina seemed to run slower to me, so using Internet Recover, should I delete volume HD-Data first followed by HD and then reinstall Mojave.
I have been backing my files up to a couple of portable HDD’s.

Thanks Gpo

 

[GPO]

Hi Fishrrman,
Thanks for getting back to me, since my original post I have got my Mac running on Mojave although sometimes it freezes or I cannot shut it down. I think the trouble lies with the two volumes created when I upgraded to Catalina macOS HD and macOS HD-Data, both are nearly full and HD-Data has the same files as HD. Also I have run the First Aid disk utility on both volumes and HD-Data shows numerous Directory errors but no disc errors.
I think I need to go for a clean install, I will stick with Mojave, Catalina seemed to run slower to me, so using Internet Recover, should I delete volume HD-Data first followed by HD and then reinstall Mojave.
I have been backing my files up to a couple of portable HDD’s.

Thanks Gpo

 

[Fishrrman]

"I think the trouble lies with the two volumes created when I upgraded to Catalina macOS HD and macOS HD-Data, both are nearly full and HD-Data has the same files as HD. Also I have run the First Aid disk utility on both volumes and HD-Data shows numerous Directory errors but no disc errors."

The solution to this is:
- back up your personal data
- boot to INTERNET recovery
- COMPLETELY ERASE the internal drive to remove all previous installations and data
- Re-install the OS
- Restore your personal data.

See my reply 2 above.

 

[GPO]

Hi Fishrrman, Apologises for late reply been away, I eventually got my Mac working again on Mojave using Internet Recovery after three tries. I had to install Mountain Lion first, then El Capitan then Mojave but on the first two try’s I was left with various dir errors on the Hd, I then installed Mountain Lion, Sierra, High Sierra and Mojave and this worked with no disc errors.

thanks for all your help.

Gpo

 

[Fishrrman]

"I had to install Mountain Lion first, then El Capitan then Mojave but on the first two try’s I was left with various dir errors on the Hd, I then installed Mountain Lion, Sierra, High Sierra and Mojave and this worked with no disc errors."

That sounds like a "long and winding road" to "get back to where you once belonged" !