Installing High Sierra on a 2010 iMac

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Installing High Sierra on a 2010 iMac

I have a friend who owns a 2010 iMac with a bad drive. I was able to load the OS and run diagnostics under Disk Utility, only to discover that the drive was damaged, as expected. Several attempts to repair the disk were unsuccessful, so I'm now trying to help him recover the apps and data, then format then reformat and reinstall. Hardware & OS is as follows...

Model Name: iMac

Model Identifier: iMac11,2

Processor Name: Intel Core i3

Processor Speed: 3.2 GHz

System Version: OS X 10.10.5 (14F2511)

Kernel Version: Darwin 14.5.0

Unfortunately, my "friend" has NEVER done a system backup, nor recorded App serial numbers and/or license info, etc. (Yes... I am indeed embarrassed to refer to him as "friend") ;-(

My hope was to use the external drive to first make a Time Machine backup, then (as a second safeguard) also manually do a straight file transfer of the data files. There's no guaranty that reformatting the drive will fix the its issues. But this seems to be the greatest chance of recovering as much as possible.

To start, I emptied one of my own older USB drives, then formatted it and installed High Sierra on it (which should be the most current OS available for that model). I know it's a good install, as I can select it as a Startup Drive on one of my own older MBPs which is running under High Sierra. I cannot, however, select this drive (connected via USB) as the Startup Drive on his iMac.

Can anyone suggest a reason why this might be? Do I need to install Yosemite on the external drive (or at least something closer to his current Yosemite install), in order to select the external installation with the iMac?

Any suggestions will help.

Thank you.

iMac

Posted on Aug 21, 2022 6:39 PM

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Answer 1

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svdrifter Author

Level 1

44 points

Aug 23, 2022 8:33 AM in response to svdrifter

Never mind... I figured it out on my own. (Thanks for all the suggestions (???), nonetheless.) In the hope that this might at least help someone else, the issue was as follows...

When I created the external system drive onto which I loaded High Sierra, I formatted the drive as "Apple File System (APFS)", since this was the best option for a spinning drive for High Sierra. What I didn't consider was that "APFS" was first introduced with High Sierra. The mid-2010 iMac, however, could not see the drive and provide it as a boot source, as it only recognized Mac "OS Extended" and/or "Mac OS Extended, Journaled" formats. Once I realized this, I reformatted the drive to "Mac OS Extended, Journaled", and reinstalled High Sierra. All good.

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Answer 2

den.thed

Level 10

82,540 points

Aug 22, 2022 7:00 AM in response to svdrifter

Attempting to or reformatting a failing or failed drive, will just make recovering the data that much harder.

Try starting up from High Sierra on the external drive you made by holding the Alt (option) key.

If that doesn't work, try starting up in FireWire Target Disk Mode from your older MBP.

The next option pull the HDD from the iMac and put it into an external enclosure.

The last chance, send the HDD out for expensive professional data recovery.

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Answer 3

svdrifter Author

Level 1

44 points

Aug 23, 2022 8:54 AM in response to den.thed

I thought I addressed this, but perhaps not clearly enough...

As indicated: "My hope was to use the external drive to first make a Time Machine backup, then (as a second safeguard) also manually do a straight file transfer of the data files. There's no guaranty that reformatting the drive will fix the its issues. But this seems to be the greatest chance of recovering as much as possible."

What may not have been clear was that I was using the external drive simply to make a TM Backup and also manually copy the data. Then after using "Recovery" to reformat the internal drive, I would have a way (2 ways) to restore his data. The data itself could easily enough be restored using a simple copy. The various settings, serial numbers, passwords, etc., could hopefully be restored via Migration Assistant from the TM backup. It was simply 2-pronged approach to ensure best chances.

I did not, however, think about using "FireWire Target Disk Mode", since I was trying to fix my friend's computer and not my own. This would certainly have a good option to at least provide a faster transfer. I have about 30+ external drives of 3-5 TB in capacity. But most are fairly full, and only a couple have FireWire. I'll have to see if I can make room on one of them to temporarily do the backup. Thanks for the suggestion!

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Installing High Sierra on a 2010 iMac

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