High Sierra Installs, Boots, and Runs until reboot and then partition won't boot

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Level 1

4 points

High Sierra Installs, Boots, and Runs until reboot and then partition won't boot

Have a strange scenario that I have replicated twice now on my mid-2010 27" iMac upgrading (?) to High Sierra. :-)

The iMac has an SSD drive (disk0s2 MAC OS Extended Journaled) as its startup drive and its original hard drive as a second drive (disk1s2). Running 10.12.6 Mac OS Sierra with 24GB RAM on Intel i7 platform

High Sierra installed both times, and even booted and allowed me to login.

Each time had some browser and app issues early on so attempted to reboot the device.

Upon reboot ... it didn't reboot.

I end up without a bootable partition to select when it takes me into the administration screen for booting, timemachine restore, etc.

The only way I have found to get my iMac back and operational is to redo the partition on the SSD drive and restore my Time Machine backup. Do that and life is back to normal.

Has anyone else experienced similar symptoms, and could it be the SSD (Samsung EVO 850) causing the issues?

I understand that the partitions have changed for High Sierra

Thoughts?

shamski

iMac, macOS Sierra (10.12.6), SSD Drive Primary Boot Drive.

Posted on Dec 15, 2017 2:29 PM

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Answer 1

xmetienne

Level 2

192 points

Dec 15, 2017 4:01 PM in response to shamski

Hi there,

A quick remark:

The iMac has an SSD drive (disk0s2 MAC OS Extended Journaled) as its startup drive and its original hard drive as a second drive (disk1s2). Running 10.12.6 Mac OS Sierra with 24GB RAM on Intel i7 platform

I'm not sure if that might be the reason, especially if it was running before on 24GB RAM, but that seems strange, was it was working in the first place? Maybe more about that on: MacBook Pro: How to remove or install memory - Apple Support you make the call!

Otherwise if the install is not completed, why not trying to reboot with option key get out of the macOS install drive, select the normal drive (if possible) reboot and try installing the combo update, here is the link:

10.13.2 Combo Update

Good luck..

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Answer 2

John Galt

Level 10

140,964 points

Dec 15, 2017 3:41 PM in response to shamski

Has anyone else experienced similar symptoms, and could it be the SSD (Samsung EVO 850) causing the issues?

Many people, and yes. That particular SSD is notoriously problematic. Replace it with one from a manufacturer known to support Macs.

You installed not one but two unsupported system modifications. Apple supports a maximum of 16 GB RAM on your model iMac. Unsupported configurations will result in unexpected results. To learn how to upgrade memory refer to the Memory Upgrade Instructions in About This Mac > Memory.

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Answer 3

shamski Author

Level 1

4 points

Dec 15, 2017 4:39 PM in response to shamski

Everything has been working fine for about 2.5 years under the 24GB or RAM - until now potentially. It does exceed the spec'd limit for the Imac model, although many third parties do report no issues of exceeding this threshold that I've seen. Point taken though and it is easy to remedy if that is the issue in the installation corrupting on a reboot.

As to the Samsung EVO 850, again it appears to be a mixed view of the EVO and Mac OSX. Many third-party sites recommend it if doing an older Imac upgrade, and others do not and recommend only Apple-Endorsed products. If needed i can rule out the SSD by making the original drive the boot drive and putting High Sierra on it to see if it works reliably which may end up being the logical path here.

Regarding whether the installation on my previous 2 attempts completed fine ... I believe so from an auto-installer view of things I was able to login to the new updated OS, and even work within although there always seemed to be issues such as significant browser delays, overall slow performance, etc. Then a reboot brought things crashing down.

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Answer 4

John Galt

Level 10

140,964 points

Dec 15, 2017 4:55 PM in response to shamski

I am not interested in arguing the merits of various unsupported configurations. It's a waste of my time. You asked a specific question, and I answered it.

You installed macOS High Sierra on hardware that has been modified in a manner Apple does not support and has no interest in testing. Now you're experiencing problems. That is to be expected. Proceed on the basis of that knowledge.

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