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Turning kext signing back on

C

camner

macrumors regular
Original poster
Jun 19, 2009
245
18
I have disabled kext signing in order to run TRIM on 3rd party SSDs (via disk sensei/TRIM enabler). I had to restore my system from a backup, and although that backup was made AFTER disabling kext signing, I get the dreaded "grey stop sign" upon boot after the restore was done.

I know I need to turn back on kext signing so the machine will boot. Cindori's website giving instructions on how to fix this has "exceeded its bandwidth" and therefore is not accessible.

Does anyone have those instructions so I can get going again?
 
Well, unfortunately Cindori's instructions didn't work (well, they didn't work for me...probably something I did wrong). I first tried the first set of instructions that aim to restore the ability to boot but keep TRIM enabled. Still got the grey stop sign. FWIW, Step 8 (rebuilding the kext cache) which supposedly can take up to 10 minutes executed in seconds.

I then tried the second set of (more complex) Terminal instructions. The following command failed:
cp -r /System/Library/Extensions/IOAHCIFamily.kext System/Library/Extensions/IOAHCIFamily.kext

The error message was "System/Library/Extensions/IOAHCIFamily.kext no such file or directory"

I tried it a second time just in case my typing and proofreading skills failed me, with the same poor effect.

So, I think I'm stuck with using the Recovery partition and reinstalling OS X. Ugh! That's time consuming!

By the way, what's the difference between /System and System? Or, more precisely, I know that /System is right at the root of my boot drive ("Macintosh HD"), right? But where is System?
 
camner said:
Well, unfortunately Cindori's instructions didn't work (well, they didn't work for me...probably something I did wrong). I first tried the first set of instructions that aim to restore the ability to boot but keep TRIM enabled. Still got the grey stop sign. FWIW, Step 8 (rebuilding the kext cache) which supposedly can take up to 10 minutes executed in seconds.

I then tried the second set of (more complex) Terminal instructions. The following command failed:
cp -r /System/Library/Extensions/IOAHCIFamily.kext System/Library/Extensions/IOAHCIFamily.kext

The error message was "System/Library/Extensions/IOAHCIFamily.kext no such file or directory"

I tried it a second time just in case my typing and proofreading skills failed me, with the same poor effect.

So, I think I'm stuck with using the Recovery partition and reinstalling OS X. Ugh! That's time consuming!

By the way, what's the difference between /System and System? Or, more precisely, I know that /System is right at the root of my boot drive ("Macintosh HD"), right? But where is System?
Click to expand...

The latter is a relative path. While you’re in recovery mode, you’re mounted on the recovery partition and not your Mac (root) partition. That’s why you set the current path with cd /Volume/<volume> first, to point to your root partition. cp -r copies the directory and its contents from the absolute path /System (on your recovery partition) to your current path (the root partition), namely: /Volume/<volume>/System.

Which folders are shown when you type ls after you change the current path with cd "/Volumes/Your Disk name"?
 
Last edited:
Sorry to hear things didn't work out for you.
This is one of the main reasons I always keep an up-to-date CCC bootable backup.
I've run into your problem back a while when Yosemite first appeared, and with a bootable clone I was backup up and running again in less then 30 minutes.
 
jbarley said:
Sorry to hear things didn't work out for you.
This is one of the main reasons I always keep an up-to-date CCC bootable backup.
I've run into your problem back a while when Yosemite first appeared, and with a bootable clone I was backup up and running again in less then 30 minutes.
Click to expand...

Right you are! I DO have a bootable clone. 4 of them, in fact, which I rotate among every week (so I have a month's worth of bootable clones one for each week in the past month). I also take occasional "snapshot" clones that I keep for a long time.

Alas, restoring from the bootable clone did NOT get me up and running again. I could boot from the clone without a problem, and I could copy back to my boot volume without a problem, but the newly "cloned back" volume gave me the dreaded "grey stop sign."

What I ended up doing was booting into the Recovery partition and reinstalling Yosemite. It took about 90 minutes for the process to complete, but I can now boot. I haven't yet had the time to see if anything odd happened in that process or whether I'm really back to status quo ante (other than that I know after the reinstall TRIM is not enabled)
 
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