Can't boot from SSD following security update

[maythyme]

For some time I have been booting my late 13 iMac from an external SSD. I found that the SSD gave hugely improved speed and performance. I run Catalina on the SSD but have kept High Sierra on the Hard Disk for occasional use with older applications.

After installing an Apple update this week – I think it was a security update my Mac will no longer boot from the SSD and reverts to booting from the Hard Disk. In the startup preferences the SSD is shown as the boot disk but the machine will only boot from the Hard Disk.

I have tried restoring both the Hard Disk and the SSD from Time Machine backups. I have also reset the PRAM and SMS but to no avail.

If I hold down the ALT key on startup the usual menu of startup disk options doesn't appear and the machine continues to boot into High Sierra on the Hard Disk.

If I disconnect the SSD and restart holding down the ALT key the menu of startup options DOES appear. If I then plug in the SSD it appears as a startup option and if I select it the Mac finally boots up from the SSD. Everything then works fine but if I shut down or restart I go back to square one and the machine boots from the Hard Disk once more.

Now despairing! Any suggestions much appreciated!

 

[mdgm]

Maybe try disabling SIP?

Boot into the Recovery Partition, open the terminal and enter

csrutil disable

and hit enter.

Then see if you can boot off the external as before the security update.

Edit: I would try the NVRAM reset suggested by DeltaMac below first.

 

[DeltaMac]

Try an NVRAM reset. That will reset the startup disk setting, so after doing that reset, you will then need to reset the Startup Disk pref pane to your external drive.

 

[BPN84]

Having the exact same issue. 2013 iMac won’t boot from external SSD.

Doing a full time machine restore. Will have to avoid this update.

 

[BPN84]

For some time I have been booting my late 13 iMac from an external SSD. I found that the SSD gave hugely improved speed and performance. I run Catalina on the SSD but have kept High Sierra on the Hard Disk for occasional use with older applications.

After installing an Apple update this week – I think it was a security update my Mac will no longer boot from the SSD and reverts to booting from the Hard Disk. In the startup preferences the SSD is shown as the boot disk but the machine will only boot from the Hard Disk.

I have tried restoring both the Hard Disk and the SSD from Time Machine backups. I have also reset the PRAM and SMS but to no avail.

If I hold down the ALT key on startup the usual menu of startup disk options doesn't appear and the machine continues to boot into High Sierra on the Hard Disk.

If I disconnect the SSD and restart holding down the ALT key the menu of startup options DOES appear. If I then plug in the SSD it appears as a startup option and if I select it the Mac finally boots up from the SSD. Everything then works fine but if I shut down or restart I go back to square one and the machine boots from the Hard Disk once more.

Now despairing! Any suggestions much appreciated!

Thank you for at least finding that you can boot from the SSD if you unplug it and plug it in at the startup screen! You’re the only person I’ve seen that found this workaround.

Hopefully Apple fixes this ASAP

 

[DeltaMac]

I would likely download the latest Catalina installer, make a new USB bootable installer from that.
Boot to the installer, reinstall Catalina on your SSD.

Latest Catalina installer from Apple was posted on 11.11.2020, version 10.15.7, build 19H15

 

[stynz]

I have exactly the same problem, happened after the last security update. My workaround is to disconnect all USB external drives, boot the iMac and finally plug the other external drives (Time Machine).
If I don't do this, either the Mac boots in an old recovery partition (that does not manage APFS!!!) or in the better case in a High Sierra partition installed in the internal HD.

 

[DeltaMac]

I would try to clear the boot drive selection at this point...
Reboot holding Opt-Command-P-R, which is an NVRAM reset.
When you hold those keys during a reboot, you will hear a boot chime (or see a video reset on Macs that don't have a boot chime). Continue to hold the same 4 keys until you hear the boot chime twice. On the third chime, release the keys, except continue to hold the Option key. Choose your correct boot drive from the boot picker screen, and press return to boot to your system -- getting to the important part here: When you get to the desktop, open your System Preferences, Startup Disk pane. Unlock the pane, and select your correct boot drive. (The NVRAM reset has un-set your startup disk, and just needs to be set again) That process should fix you up.

 

[mgroot]

Had the exact same problem, resetting the NV/PRAM had no effect for me. I ended up having to leave a USB port empty (one of my externals has 2 extra USB ports so I am now using those) and now it boots normally again from the external SSD

 

[mgroot]

Ok, my solution above didn't quite fix it. It now looks like it'll boot from the internal on the first boot after powering up and if I then restart it will boot from my external SSD without having to hold Option to pick the boot drive.

I've filed a bug report for this

 

[DeltaMac]

Which drive do you have selected in your Startup Disk pane?
Remember that you have to unlock that pane to check the setting.

 

[mgroot]

The external SSD

 

[honestone33]

Hmm, just saw that security update, which was released on December 16th. I just downloaded, but will install it myself in a few minutes. (Am now in my Big Sur environment). Hopefully after I apply it, will have no issues. Fortunately, I have two SuperDuper! backups I made yesterday for both of my Macs (Catalina), which of course is prior to the Security update.

 

[along99]

I would try to clear the boot drive selection at this point...
Reboot holding Opt-Command-P-R, which is an NVRAM reset.
When you hold those keys during a reboot, you will hear a boot chime (or see a video reset on Macs that don't have a boot chime). Continue to hold the same 4 keys until you hear the boot chime twice. On the third chime, release the keys, except continue to hold the Option key. Choose your correct boot drive from the boot picker screen, and press return to boot to your system -- getting to the important part here: When you get to the desktop, open your System Preferences, Startup Disk pane. Unlock the pane, and select your correct boot drive. (The NVRAM reset has un-set your startup disk, and just needs to be set again) That process should fix you up.

I face a very similar problem and somehow my iMac disregards the Opt-Cmd-R-P and boots from the internal HDD. What other options do I have?

For the sake of completeness let add the full story:

For a couple of months I've been successfully running my 2013 iMac from an external SSD (for speed reasons). Initially, the SSD was a clone of my internal High Sierra Macintosh HD. Since then, program updates and content were added successfully.

Today I performed a successful upgrade to Catalina. The system looked fine.

I then performed another recommended security + Safari update. When completed the Mac booted to the old High Sierra OS from the internal HDD!

I used the Startup preferences while in High Sierra to set the external 10.15 OS X SSD as boot disk - no effect! still booting from HDD.

I tried rebooting into recovery mode (cmd+R+power) - no effect! the boot process form HDD continued regardless of that. This key combination worked fine when I cloned my HDD.


This is a terrible mess! I'm afraid to try anything else not to aggravate the situation.

Any way to set it right? i.e. boot from the external Catalina SSD

Comments:

1) The external SSD is now displayed in Finder as two disks: Macintosh HD and Macintosh HD - data. This was probably created during the upgrade to Catalina. No idea why. The internal HDD was never partitioned through all previous OS X upgrades.

2) If worse comes to worst, I have a Time Machine backup of the SSD prior to the Catalina upgrade. Not sure how to use it under the circumstances.

Thanx

 

[mdgm]

If you open System Information what is your Model Identifier and the "Boot ROM" version? I wonder if your system didn't update the Boot ROM and perhaps that update is needed to boot the Catalina version you have on the external SSD.

You may need to update the Mac OS on the internal hard drive/SSD to update the Boot ROM if your Boot ROM is on a very old version.

 

[Phil B]

For some time I have been booting my late 13 iMac from an external SSD. I found that the SSD gave hugely improved speed and performance. I run Catalina on the SSD but have kept High Sierra on the Hard Disk for occasional use with older applications.

After installing an Apple update this week – I think it was a security update my Mac will no longer boot from the SSD and reverts to booting from the Hard Disk. In the startup preferences the SSD is shown as the boot disk but the machine will only boot from the Hard Disk.

I have tried restoring both the Hard Disk and the SSD from Time Machine backups. I have also reset the PRAM and SMS but to no avail.

If I hold down the ALT key on startup the usual menu of startup disk options doesn't appear and the machine continues to boot into High Sierra on the Hard Disk.

If I disconnect the SSD and restart holding down the ALT key the menu of startup options DOES appear. If I then plug in the SSD it appears as a startup option and if I select it the Mac finally boots up from the SSD. Everything then works fine but if I shut down or restart I go back to square one and the machine boots from the Hard Disk once more.

Now despairing! Any suggestions much appreciated!

I'm now in the club, too. Same situation, after security update. ANy NVRAM etc won't work neither, as shortcuts are not recognized during startup (maybe because wireless originao apple keyboard. Funny btw giving the advice that you might use a wired one ;-)
Are there any updates on the problem? It's terribe working from my late 2013 iMac with internal HD instead of my external SDD. Any more tips welcomed.

Cheers and good luck to us all ...

 

[along99]

If you open System Information what is your Model Identifier and the "Boot ROM" version? I wonder if your system didn't update the Boot ROM and perhaps that update is needed to boot the Catalina version you have on the external SSD.

You may need to update the Mac OS on the internal hard drive/SSD to update the Boot ROM if your Boot ROM is on a very old version.

Thanks for your attention
As to your questions, the details revealed in System Info:

Model Identifier: iMac14,2
Boot ROM Version: 429.0.0.0.0

Boot ROM update sounds like a one way route, no going back, isn't it? failing there and hasta la vista.

Anyway, can you tell from the info provided whether the problem is categorically the ROM version?
Thanx

 

[mdgm]

Hmmm. Was just a guess that it may not have been updated. That looks like an up to date Boot ROM version. So I guess the cause of the problem is something else.

A wired keyboard is definitely worth a try to do a reset.

 

[along99]

I don't think I've seen a wired keyboard lately
I can connect my Magic Keyboard 2 with its charging cable to the iMac. Would it be considered to be wired? (I guess not)
Thanks for your effort. I hope someone can come up with a new idea.
It seems I exhausted all the ideas with no success.
BTW, any idea how I can use my Time Machine backup to revert the SSD to its 'form' before the upgrade to Catalina?
If I do that, Will the ROM updated by Catalina work with High Sierra?

 

[along99]

BTW, further to you questions I read some more on the net and run the eficheck below is its result:

Last login: Thu Dec 31 11:36:46 on console
alons-iMac:~ along$ /usr/libexec/firmwarecheckers/eficheck/eficheck --integrity-check
EFI Version: IM142.88Z.F000.B00.2012022038
Matching allowlist not found in EFIAllowListShipping. Searching in EFIAllowListAll.
This system does now allow downloading background update data. Canceling.
Primary allowlist version match not found for version IM142.88Z.F000.B00.2012022038.
I think it is inconclusive.

 

[along99]

Good news, after half an hour on phone with Apple's support, it works. For now.
The solution was SMC reset, which is: unplug all accessories, unplug from AC power for 15 sec., plug in again, wait 10 sec., and power up iMac.
I was astonished by this simple solution!

Few reservations though:
1) Maybe the other steps I performed (such as NVRAM reset) also played an important role.
2) Surprisingly, now that its back on, Catalina recommends to perform 2020-01 security update. I'm sure I did that before, and if I'm not wrong, the 'disaster' happened immediately afterwards. I'm avoiding it for the meantime. Apple Support said there is no known problem with it and I could try that in future.
3) The SSD upgrade to Catalina seems to have affected the iMac operation when it booted to High Sierra from The HDD. I'm not sure how it will perform should I need to boot again from HDD. Maybe the SMC reset corrected that as well. Who knows...
4) I'm still concerned if my iMac will continue to properly work from SSD for a prolonged period.

 

[mdgm]

Reset the SMC of your Mac – Apple Support (AU)

The SMC is responsible for managing power on your Mac. Resetting it can resolve certain uncommon issues related to power or thermal management.

support.apple.com

Apple says that SMC manages the provision of power to the USB ports. So maybe it was taking too long for sufficient power to be provided to the USB ports and thus they weren't detected early enough in the boot process to boot off them.

 

[Phil B]

Good news, after half an hour on phone with Apple's support, it works. For now.
The solution was SMC reset, which is: unplug all accessories, unplug from AC power for 15 sec., plug in again, wait 10 sec., and power up iMac.
I was astonished by this simple solution!

Few reservations though:
1) Maybe the other steps I performed (such as NVRAM reset) also played an important role.
2) Surprisingly, now that its back on, Catalina recommends to perform 2020-01 security update. I'm sure I did that before, and if I'm not wrong, the 'disaster' happened immediately afterwards. I'm avoiding it for the meantime. Apple Support said there is no known problem with it and I could try that in future.
3) The SSD upgrade to Catalina seems to have affected the iMac operation when it booted to High Sierra from The HDD. I'm not sure how it will perform should I need to boot again from HDD. Maybe the SMC reset corrected that as well. Who knows...
4) I'm still concerned if my iMac will continue to properly work from SSD for a prolonged period.

I did SMC and NVRAM reset, too, beside installing a pretty fresh Catalina and this alll for several times in different order. Finally what worked (maybe in combination) waste disconnect all other stuff on my USB (other disks and some Audio/Midi peripherals). iMac booted finally from external again and then I connected the other devices when airing in finder. BUT then: Another SSD Disk (same as boot volume, a Crucial X8 2TB) showed reading speed of 20 MB/s (fairy enough more than a floppydisk..) instead of the usual 440-460. G-Drive 6TB 7200rpm HD lacked too, around some 30 MB/s (even funny that the HD was faster than the SSD, I think that was her one only time being the winner of the race)

. Did the same again, switched ports, SMC and NVRAM Reset, and now at least both SSD are back to some 420 (bit less than usual, but anyway). 7200 HD is around 150, what's fine too. Another Seagate Backup 6TB 5400 HD can't be tested with Blackmagic, cause it's the Time Machine ReadOnly Volume. And last some tiny WD MyPassport 2TB is around some 50MB/s.

So for now everything looks more or less fine. But there's deffo two things I won't do soon again now:
1st: Shut down my iMac (I let him sleep instead, sorry Greta, for killing trees...)
2nd: Insatll this ****** security update again

Although Apple states there's nothing know, it is definitely this. Cause everyone with problems had the same. Installing 2020-001 Update, and --baaang--. Pretty obvious.

But of course, most nowerday Mac Users have the MacBook, and maybe some tiny SSD just to store some documents more. So they won't boot from external, neither cause heavy bandwidth 4k Video or additionally in my case instrument Library Samples, which need speed to load into ram. So the typical user won't report some strange behaviour, maybe just wondering, why the lates powerpoint takes one sip of water more ;-)

 

[mgroot]

It took me several tries as well, to find an order in which everything booted up again as it was supposed to.
I've filed a bug report for this (and linked to this thread in it) so they at least will have the data for his somewhere in Apple