Error installing High Sierra on Fusion Drive

[spang1974]

After my first attempt at upgrading to High Sierra left me with the loading kernel cache error documented in the 1st post, I had to boot into Recovery and run First Aid to recover my Fusion Drive.

I then used CCC to clone my Sierra install to an external HD. I then proceeded to upgrade this external Sierra install to HS, or so I thought. After the upgrade completed, I booted from the external HD, only to find it was still running Sierra. I then unplugged the external drive, and rebooted from my Fusion Drive to find it was running HS! I'm not sure if I chose a wrong option somewhere, but it's all good now.

DDT did you run the HS Installer from the SSD? I wonder if that is the key? Maybe you ran the HS installer from the SSD and inadvertently upgraded your fusion instead of the SSD?

 

[spang1974]

Yes, I ended up doing what many others in this thread did. Using Carbon Copy Cloner, I cloned my Fusion Drive to an external hard disk, installed High Sierra on that, then cloned it back to my Fusion Drive.

Thank you

 

[ddt]

DDT did you run the HS Installer from the SSD? I wonder if that is the key? Maybe you ran the HS installer from the SSD and inadvertently upgraded your fusion instead of the SSD?

It's very possible. I thought I had booted from the external drive (HDD, not SSD), and selected it as the target for installation, but whatever I did wrong it worked out.

 

[Allezxandre]

Anyone with another solution yet? My Fusion Drive is way too big to have a full backup of it.

 

[Adam1203]

Anyone with another solution yet? My Fusion Drive is way too big to have a full backup of it.

I'm in the same boat. I'm just waiting until the HS update comes out that support APFS on Fusion Drives. I tried doing the install, but got the same error as the OP. I was able to fix it by doing a reinstall of Sierra.

 

[slosho]

Like many others, the only way I was able to get High Sierra running on my Fusion drive was to first install it to a regular HDD and then clone it over to the Fusion drive. This solution was working fine—until I tried to install the Supplemental Update. Once I downloaded the update, I ran into the kernel cache error again.

This time, however, I examined the boot files before and after attempting the update and figured out a solution. I don't know if something like this will work for the initial High Sierra install, but at least it solves the update problem. Here's what I did:

1. Attempt to install the update via the App Store like normal. Allow the computer to restart.
2. Instead of trying to boot High Sierra (which will fail), boot into Recovery and use the Startup Disk selector to select the macOS 10.13 volume.
3. Click the reboot button. (The boot partition will be repaired and Clover should now be able to boot the system normally again.)
4. Use

   diskutil mount /dev/diskXsY

   in Terminal to mount the Recovery partition, replacing X and Y with the appropriate disk and partition numbers. (Note: I did this while logged into Recovery mode from a different hard drive. A USB installer should also work. I haven't tested it, but I think I could have also done this while booted up normally.)
5. Navigate into the Recovery volume and drill down to "com.apple.boot.P/Library/Preferences/SystemConfiguration" (Note: The letter after "boot" may be different on your machine.)
6. Open com.apple.Boot.plist and find this line:

   <key>Kernel Flags</key>

7. Right below this line, there is a pair of

   <string>

   tags with nothing between them. Enter the following between those tags:

   -rootdmg-ramdisk auth-root-dmg=file:///macOS%20Install%20Data/Locked%20Files/BaseSystem.dmg

8. Save the file.
9. Reboot and select the usual boot volume in Clover.

Once I did this, the update began to install during the boot routine. The computer rebooted automatically. Once everything was done, I checked the build number in "About this Mac" and confirmed that the update had been applied. The hack I made to the boot file was even removed automatically.

I don't have a setup to test it on, but I wonder if this solution (or something like it) could also be used to solve problems updating from Sierra to High Sierra. In any case, I hope this helps anyone who has run into the same problem as I did. This should avoid the need to start from scratch each time a new update comes out. (At least until Apple gets APFS to work on Fusion drives.)

 

[43n79w]

I used this approach to initiate the supplementary update installer. However, I'm getting the "The path /System/Installation/Packages/OSInstall.mpkg appears to be missing or damaged" issue. I've removed EmuVariablesUefi-64.efi and tried a bunch of other things like disabling a second SSD I have in my box. But I can't seem to get past this error. Anybody have some suggestions?

UPDATE:
Interesting. I went through the steps again but ensured that when I edited the com.apple.boot.plist file that I booted off a USB drive. This time everything worked!

 

[Adam1203]

Like many others, the only way I was able to get High Sierra running on my Fusion drive was to first install it to a regular HDD and then clone it over to the Fusion drive. This solution was working fine—until I tried to install the Supplemental Update. Once I downloaded the update, I ran into the kernel cache error again.

This time, however, I examined the boot files before and after attempting the update and figured out a solution. I don't know if something like this will work for the initial High Sierra install, but at least it solves the update problem. Here's what I did:

1. Attempt to install the update via the App Store like normal. Allow the computer to restart.
2. Instead of trying to boot High Sierra (which will fail), boot into Recovery and use the Startup Disk selector to select the macOS 10.13 volume.
3. Click the reboot button. (The boot partition will be repaired and Clover should now be able to boot the system normally again.)
4. Use

   diskutil mount /dev/diskXsY

   in Terminal to mount the Recovery partition, replacing X and Y with the appropriate disk and partition numbers. (Note: I did this while logged into Recovery mode from a different hard drive. A USB installer should also work. I haven't tested it, but I think I could have also done this while booted up normally.)
5. Navigate into the Recovery volume and drill down to "com.apple.boot.P/Library/Preferences/SystemConfiguration" (Note: The letter after "boot" may be different on your machine.)
6. Open com.apple.Boot.plist and find this line:

   <key>Kernel Flags</key>

7. Right below this line, there is a pair of

   <string>

   tags with nothing between them. Enter the following between those tags:

   -rootdmg-ramdisk auth-root-dmg=file:///macOS%20Install%20Data/Locked%20Files/BaseSystem.dmg

8. Save the file.
9. Reboot and select the usual boot volume in Clover.

Once I did this, the update began to install during the boot routine. The computer rebooted automatically. Once everything was done, I checked the build number in "About this Mac" and confirmed that the update had been applied. The hack I made to the boot file was even removed automatically.

I don't have a setup to test it on, but I wonder if this solution (or something like it) could also be used to solve problems updating from Sierra to High Sierra. In any case, I hope this helps anyone who has run into the same problem as I did. This should avoid the need to start from scratch each time a new update comes out. (At least until Apple gets APFS to work on Fusion drives.)

I've setup a Fusion drive in my macOS VMWare VM. I'm going to test this now and will update to see if this will successfully work during the initial installation.

 

[cccip]

slosho,

May I ask which recovery disk needs mounting? Each of my Fusion disks got one.
After mounting the one on the boot drive, there is no "com.apple.boot.P/Library/Preferences/SystemConfiguration" on recovery partition. Just "com.apple.boot/com.apple.Boot.plist"
Second thing - once you fix bootable drive from Recovery partition, it removes supplemental files boot entry from Clover.

 

[slosho]

slosho,

May I ask which recovery disk needs mounting? Each of my Fusion disks got one.
After mounting the one on the boot drive, there is no "com.apple.boot.P/Library/Preferences/SystemConfiguration" on recovery partition. Just "com.apple.boot/com.apple.Boot.plist"
Second thing - once you fix bootable drive from Recovery partition, it removes supplemental files boot entry from Clover.

I'm not entirely sure what's happening in your situation, but here's some more background about my system.

I have a DIY Fusion drive on my hack named "Primary." Since it's a Fusion drive, it doesn't show up in Clover. Instead, I have to choose "Recovery HD" in order to boot. (I normally see two entries for "Recovery HD." One is the normal boot routine; the other is the actual recovery mode.)

On my hack, each of the fusion drive's physical disks has an Apple_Boot partition. The one on the HDD is named "Recovery HD" and the one on the SSD is named "Boot OS X." The second one (Boot OS X) never shows up in Clover, so I always boot from "Recovery HD." This is the one that I mounted to edit the file. (The update installer seems to modify both Apple_Boot partitions, but since I can only reliably see "Recovery HD" this is the one I tried to modify.)

Interestingly, the "Boot OS X" partition did show up after running the first stage of the Supplementary Update installer. However, choosing it in Clover resulted in a kernel cache error. (As documented previously, choosing "Recovery HD" also resulted in a kernel cache error.)

After using the Startup Disk selector to repair the boot files, the "Boot OS X" partition disappeared again from Clover, and the com.apple.boot.[X]/Library/Preferences/SystemConfiguration folder appeared on the mounted drive. I tried this sequence a few times before I figured out what to edit. From what I recall, every time I messed with things, the letter after "boot" was different.

After editing the boot.plist, I rebooted on my own (without running the installer again). The second stage of the update installer started up part-way through the boot sequence.