Mac OS X Sierra 10.12.2

Question

Level 1

7 points

Mac OS X Sierra 10.12.2

Have updated from Mac OS 10.12.1 to 10.12.2. System has an external Promise Pegasus 2 6 drive sub-system.

System was using the external drive as the "/ " (root) drive and not using the internal drive at all.

Under 10.12.1 and earlier releases of OS X booting to any external device worked.

Be aware....10.12.2 no longer even "sees" the external drive at boot time. The Option key does not show the external drive at all.

The external drive is available as a mounted device after boot.

It is possible to re-install the OS to the Promise system, but alas, it will not boot to it.

Apple tech support says that they do not support "/" devices as external drives.

Since when? I have several system setup this way for fault tolerance (using raid) which is not provided by the internal hard drive.

Have not found a work-around.

Any ideas on how to correct this deficiency?

Thanks.

iMac with Retina 5K display, macOS Sierra (10.12.2)

Posted on Dec 15, 2016 5:58 PM

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Answer 1

doorman2 Author

Level 1

7 points

Feb 6, 2017 11:45 AM in response to doorman2

Problem solved. Mac OS 10.12.3 fixed the original issue. The Promise Tech Pegasus R2 now functions fully as a "/" device.

Also set the NVRAM properties.

sudo

nvram enable-legacy-orom-behavior=1

Only issue is that you must use the Option Key at boot to select this device. (No remote booting!)

System Preference Startup Disk does not work.

Doorman2

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Answer 2

GeeD

Level 6

9,179 points

Feb 25, 2017 8:56 AM in response to doorman2

I have an OWC Mercury Elite Pro Dual set up as Raid 0 and connected to my Mac Pro (2013) via Thunderbolt. Two partitions are used for system clones created by Superduper. I have just discovered that I cannot boot from them (running OS 10.2.3) any longer though I used to be able to. Neither the NVRAM setting change nor the opt-shift-commd-period make the partitions appear at start-up with opt key depressed.

Fortunately, booting is still possible when I connect the drive via the alternative USB interface.

It seems that the 10.12.3 OS update has not solved the problem for all external drives connected by Thunderbolt.

Geoff.

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Answer 3

ricphil

Level 1

14 points

Mar 27, 2017 10:41 PM in response to Marcel Weidmann

Marcel,

lost access to my RAID!! drive 2 months ago when updated to Sierra

tried your terminal command, but got following error message:

nvram: Error setting variable - 'enable-legacy-orom-behavior': (iokit/common) general error

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Answer 4

Timbuktu

Level 3

790 points

Dec 15, 2016 6:20 PM in response to doorman2

Glad I checked prior to updating to 10.12.2. Are you saying that I can no longer use an external USB drive to boot up the OS? I have Sierra 10.12.1 installed on an USB3 stick to test drive the OS before updating my main system, and it has served me well for several OS X releases. If this is no longer possible that would be a big blow.

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Answer 5

John Galt

Level 10

147,162 points

Dec 15, 2016 6:26 PM in response to doorman2

Apple tech support says that they do not support "/" devices as external drives.

I think Apple Support didn't understand what it was you want to do. Of course you can boot from an external device. You don't even need a functional internal boot volume. Please read How to set up and use an external Mac startup disk - Apple Support.

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Answer 6

Dec 16, 2016 12:28 AM in response to doorman2

Hi doorman2,

we have the same problems since 10.12.2 - we use a Pegasus2 R Series 4-bay as Data- and System Raid with a Apple Mac mini 3,0 GHz Intel Core i7 16 GB connected via Thunderbolt. The Pegasus is configured as RAID 5 with 6TB usable storage with 150GB for System macOS and 5,85 TB as data storage.

Since the update macOS 10.12.2 the Mac cannot boot from the RAID anymore.

We checked the RAID with other Macs and the volumes are visible at the Hard Drive Utility and also the whole folderstructur at the "Finder" is visible and usable - means the RAID is working totally correct.

We updated other Macs to macOS 10.12.2 and had the same effect - System and Data Volume are visible but not bootable anymore.

We checked also different other external Thunderbolt volumes and they were all bootable, only the Pegasus Raid isn´t shown as bootable volume anymore. So it seams that this is not a Apple Thunderbolt problem. We have send a ticket to Promise and wait for answer.

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Answer 7

doorman2 Author

Level 1

7 points

Dec 16, 2016 5:33 AM in response to Timbuktu

Hi Timbuktu,

I can only comment on my setup. iMac 27" 5k with Promise Tech Pegasus 2 R6 (raid 5 with hot spare). Connection is Thunderbolt.

No issue on 10.12.1, except on rare circumstances I would have to use the Option key to select boot device, otherwise would ignore Boot Drive settings and boot to internal hard drive.

I don't have any bootable USB devices setup to try.

Doorman2

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Answer 8

doorman2 Author

Level 1

7 points

Dec 16, 2016 5:38 AM in response to Till Heppner

Till Heppner,

I also contacted and spoke to Promise technical support.

Promise said that they did not know of the problem. Had no suggestions.

I suggested they contact Apple as a supported vendor (Apple sells Promise hardware) and they said they don't have a path to Apple OS people. Strange!

I suspect that maybe a timing issue as the Pegasus R6 does not come ready immediately waiting on Thunderbolt activity. If this is issue then Apple has changed something in the boot.

Doorman2

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Answer 9

Dec 19, 2016 5:19 PM in response to doorman2

I think, it has to do with the fix in 10.12.2 for the circumstance, that one was able to fetch a FileVault2 password with help of a connected Thunderbolt device. Apple might have changed something in EFI, that PROMISE devices don't like.

Have a look at

http://blog.frizk.net/2016/12/filevault-password-retrieval.html

Hope, there will come an update/patch either from a Apple or from PROMISE.

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Answer 10

doorman2 Author

Level 1

7 points

Dec 19, 2016 5:19 PM in response to Olaf Seifert

Olaf,

Thanks, this sounds as good an explanation as has come forward so far.

I am working with Apple and will send them your information to see if we can get them on the right track.

Appreciate your effort.

Doorman2

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Answer 11

Dec 21, 2016 6:29 AM in response to doorman2

Here is a workaround from Apple:

How to set up and use an external Mac startup disk - Apple Support

"If you can't select your startup disk or start up from it"

It works 🙂

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Answer 12

Dec 21, 2016 6:37 AM in response to Till Heppner

Yes, it does. I can confirm.

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Answer 13

doorman2 Author

Level 1

7 points

Dec 21, 2016 12:09 PM in response to Till Heppner

Hi Till,

I tried to use the suggestion that you pointed to including the sudo nvram enable-legacy-orom-behavior=1.

After this command was executed, the external raid device was still not found at boot. Now when using the Option key method, the computer never provides any options to boot from, only a black screen.

Fortunately the iMac still boots to the internal hard drive if you simply power on.

Thanks for the research.

Doorman2

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Answer 14

doorman2 Author

Level 1

7 points

Dec 21, 2016 12:10 PM in response to Olaf Seifert

This solution did not work for me.

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Answer 15

Yansolo

Level 1

4 points

Dec 21, 2016 12:52 PM in response to doorman2

I've just updated my Mac Mini with a Pegasus R4 to 10.12.2 and I can't boot on it anymore too.

I can't see my Pegasus as a startup disk at boot pressing the alt key, but I can see it using a USB OSX install key as a boot device, then I'am able to choose the Pegasus as a startup disk.

But after it reboot, it can't see the Pegasus again and doesn't boot ...

Edit : I 've booted on the USB key again and launch the terminal then typed :

nvram enable-legacy-orom-behavior=1

I'am able to bbot again on my Pegasus now !

Thanks a lot Tim 😉

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