macOS could not be installed

[ColinBird]

All was going according to the script until I started the install. I pressed restart expecting the iMac to start up again, but no, it was the MacBook. I didn't dare interrupt the process for fear of corrupting the OS on that. After appearing to stall for a long time at 44 minutes, the installing message is now slowly decrementing the time remaining. Assuming it does eventually complete, I have my fingers crossed that the MacBook will still be usable. Assuming that it is, I will have to retry the install on iMac, but do not know how to force the installer to work on that rather than the MacBook (again).
I very much appreciate all the help you given me so far and hope you won't mind seeing me through this difficulty. BTW, I'm using my iPad to send this message!

 

[honestone]

A couple of things to confirm:

1. Did you launch Disk Utility and the "Install macOS High Sierra" apps on your laptop? Those were the first steps to take after you connected the iMac in Target Disk Mode.

2. Assuming you did that, what did Disk Utility tell you when it was Erasing and Formatting the iMac's internal drive?

3. Assuming you launched the "Install macOS High Sierra" file that was in the Applications folder on the laptop, did you choose the iMac's drive for the destination of the installation? As long as you did that, it would not install on your MacBook.

As the installation progressed, when did you press restart? I am thinking that should have been OK, as it was restarting the MacBook to continue the installation onto the iMac.

This statement is confusing:

"I will have to retry the install on iMac, but do not know how to force the installer to work on that rather than the MacBook (again)"

The instructions were to launch the installer on the MacBook, then point to the iMac's internal drive for the installation to install all the files associated with High Sierra. Is that what you did?

Again, as long as you pointed to the iMac's internal drive for the installation of High Sierra, that is where all the "stuff" would be installed, not on the MacBook.

 

[ColinBird]

1. Yes
2. It said the iMac disk was OK
3. I didn't see (or didn't notice) an option to select a disk, so assumed that the installer was still pointing to the iMac disk (as with Disk Utility)

The installation process said restarts would be necessary, so I pressed the button to start it, still assuming it was pointing to the iMac.

The intent of my (poorly worded) question was to ask how I could select the iMac disk second time round.

It looks as though the install on the MacBook might be nearing its end (about 85% now)

 

[honestone]

I suspect there was a choice of which disk to select for the installation. But the "default" one would have been for the drive on the MacBook. I'll explain what I just did to "confirm" this.

I am entering this on my late 2012 Mac Mini, and the internal drive (actually SSD) on it is called "Macintosh SD". One of my external devices (actually a Samsung 850 Pro 512 gig SSD) has 3 partitions, with two of those partitions being named "Mac Mini Backup SSD" and "MacBook Air Backup SSD". They each contain SuperDuper!, bootable backups I did for each of my Macs back on Saturday (like I always do). Also, on both the Mac Mini and each of the SuperDuper! backups, I have a folder entitled "Upgrades", and a sub folder entitled "OS 10.13 Upgrades", and within those folders I have a copy of the "Install macOS High Sierra" file (you did remember to make a copy of that file after you downloaded it, and prior to connecting the iMac in Target Disk Mode, right?).

So, I connected that external SSD to one of the USB 3.0 ports on my Mac MIni, went to System Preferences (on the Mini), selected Startup Disk, selected the "Mac Mini Backup SSD" choice from there, and restarted my Mac Mini from that "Mac Mini Backup SSD" bootable backup. The machine then did that, and when I got to the backup's desktop, I navigated to the "OS 10.13 Upgrades" folder I mentioned above, and launched the "Install macOS High Sierra" file. (I should mention that on that desktop, I did see icons for "Mac Mini Backup SSD", "Macintosh SD", and "MacBook Air Backup SSD"). After the Welcome screen, and then the license acknowledgement screen, the next one showed the disk "Mac Mini Backup SSD" as the "top" one. But right under that was a "box" that said "Show All Disks". When I clicked on that, it then showed the three disks "Mac Mini Backup SSD", "MacBook Air Backup SSD", and "Macintosh SD". If I was doing a new installation, I would have chosen "Macintosh SD".

All of that would be similar for your 2 machines. The "initial" disk, where the file "Install macOS High Sierra" was (after you downloaded it (and hopefully made a copy)), would have been the name of the one on your MacBook. As long as you formatted the iMac's internal drive as MacOS Extended (Journaled, GUID Partition Map), then the "Show All Disks" box should have been there, and selecting that would have allowed you to choose the name of the iMac's internal drive (the name you gave it after Disk Utility Erased and Formatted it).

I suspect that if you just clicked Continue on that "disk" screen (ie, did not click on "Show All Disks"), then High Sierra is being installed onto the MacBook. As long as you made a copy of that "Install MacOS High Sierra" file on another location on your MacBook, you'll be able to replicate the process again to install High Sierra onto the iMac's internal drive.

In actuality, after the installation is complete, and assuming the restart is from the MacBook, once you get to its desktop, you should be able to double click on the iMac's drive and see if there is anything on it.

 

[ColinBird]

1. The MacBook install finally completed about 10 minutes ago. Since then, it has been doing what I expect, but is running very slowly. That *might* be improving but the jury is still out.
2. I did format the disk as MacOS Extended (it's the default). At first the Partition button was greyed out, but I have now been able to create two partitions.
3. I did save a copy, which Is taking a long time to copy back to Applications, so I'll send this update while I wait.
4. The next step will be to try the install again, looking for "Show All Disks" this time.

 

[honestone]

OK, sounds good. You actually could have launched that "Install macOS High Sierra" file from the place you copied it to, but that's fine.

Also, when the installation onto the iMac completes, it might be wise to copy that "Install macOS High Sierra" file (should still be in that "copied" location on your MacBook) to a location on the iMac (other than the Applications folder).

Additionally, as I mentioned above, you should disable the automatic update of the Mac OS. To do that (hope you don't mind me repeating myself), here are the steps:

1. Pull down the Apple menu and navigate to System Preferences. Or click on the System Preferences icon in the Dock.

2. Select the App Store System Preference.

3. De-Select “Automatically check for updates.”. Also de-select all the boxes underneath that one.

Finally, I suspect OS 10.13.4 will be out soon. You will be able to upgrade to that (under your control) without needing to visit the App store to get the upgrade. I usually make a post on this site when such an upgrade comes out (and also some other important software), and one of the options you'll have is to download and installed the so-called Combo Updater for that release. Just look for the post I will (most likely) make when it is released.

Again, you'll be able to download and install that Combo Updater yourself.

 

[ColinBird]

We have a new twist ... I can see the two partitions on the iMac, but when I select the main one I get the message: "You may not install to this volume because it is a Mac in target disk mode."

 

[honestone]

Sorry about that. Not sure why that would be the case, as a disk in Target Disk Mode, and formatted as MacOS Extended (Journaled, GUID Partition Map) "should" be the same as my situation, where I boot from my SuperDuper! backup, select the disk on the "target" (not booted in Target Disk Mode, but still shows up anyway) machine to Erase and Format it, and then follow the steps you did for trying to install High Sierra into the disk/partition. I have done that each and every time that I want to install (or re-install) the current version of a Mac OS.

I have requested our true resident "expert" Cory Cooper to "chime in" here. He is just such a knowledgeable individual. Meanwhile, I'll keep searching.

 

[honestone]

OK, there is another possibility. Given that you have the "Install macOS High Sierra" file on your MacBook, if you have a USB Flash Drive (preferably 32 gig in size), this link describes how to make a bootable USB Installer:

http://osxdaily.com/2017/09/27/create-macos-high-sierra-bootable-installer-usb/

Note that first, you'll need to copy the "Install macOS High Sierra" file to the Applications folder on your MacBook (I think you already did that).

Once you complete that, quit on the installer screen, and remove the Flash Drive from the MacBook. Then, plug the Flash Drive into one of the ports on the iMac, and boot up the iMac, holding down the Option key. You should see a list (most likely only the Flash Drive) of bootable devices. Select that, and you should then be able to proceed with the installation.

Again, though, I am still perplexed why it would not work with your original attempt. I know that High Sierra has some new "quirks", including some that affect some applications. But Target Disk Mode is an Apple "concept".

OK, I found out that one can not install High Sierra in Target Disk Mode:

https://tidbits.com/article/17451

That is just so, so surprising! And definitely quirky!

So, it looks like you'll need to go through the "USB Flash Drive" process described above.

 

[ColinBird]

I'm truly grateful for all your help. It's getting late here, so I'm going to call it a day and return to the challenge tomorrow. That will be later on, as we have several things on, including a funeral during the afternoon.
Given what you said about being unable to install High Sierra, I reckon my first pass will be to try the process (which is now more familiar!) with Sierra. If that works, and I guess it should, Apple will no doubt subsequently nag me to upgrade!
Very many thanks again. You've been a reassuring help.

 

[honestone]

Sorry I could not help more. But yeah, if you have the "Install MacODS Sierra" file somewhere, that could be a better choice.

Let us know how it goes.

 

[ColinBird]

Unfortunately, the Sierra option isn't going to work, because when I open it on my MacBook, up comes a message saying it's too old to run on this computer. So it's going to be the memory stick, but not yet ... we have a houseful over Easter. More news later ...

 

[honestone]

Given that you have not installed High Sierra yet, V10.13.4 was released yesterday. So you might want to consider downloading it to install onto your iMac. To that, though, you'll need to either delete whatever copies you have of V10.13.3 on your MacBook, or rename them (if you are going to rename, it would be good to delete one of them, to save space).

Also, I don't understand why you got that message with Sierra. This link contains a list of which Macs one can install OS 10.12.x, Sierra, on:

https://www.macworld.com/article/3121239/macs/which-macs-can-run-macos-sierra.html

Both of your Macs are on that list. I know that Apple has been quite "anal" recently with some strange, questionable policies:

1. Sierra not available at the App Store, even via the "Purchased" tab.

2. Cannot download a new version of the Mac OS (within the "same" OS, ie, for example V10.13.4) if the file "install MacOS High Sierra" is ANYWHERE on your Mac.

3. Cannot install High Sierra on a machine that is in Target Disk Mode (you experienced that).

There are probably some others that I have not encountered yet.

 

[ColinBird]

Back on the case after a busy Easter. Creating the bootable USB drive went well and the iMac went straight to that device and began installing. I was beginning to feel optimistic as time went by, but the install halted when the message said "About 5 minutes remaining" and it's been stuck there for 45 minutes now. I'm wondering whether the next move is to hand the challenge over to Apple ...
Any thoughts? It seems cheeky to ask, given how very helpful you've been already.

 

[ColinBird]

Stop Press! I decided to give it a second try and it worked. Now to reinstate the applications and copy across the data files ...
Once more, very grateful thanks for all the help. I wouldn't be where I am now without it.
All the best- Colin

 

[honestone]

Cool! I was starting to really feel bad for you, given all the time and effort you put into this. Real glad it worked out!

Once you are done, please, please start making backups! And given all the time and effort it took, you really should consider using SuperDuper! or Carbon Copy Cloner instead of Time Machine. It is so much smoother to do either a fresh installation of a Mac OS, or a recovery from a disaster. I just "upgraded" to OS 10.13.4 with a full, clean, fresh installation via my SuperDuper! backup, and the process went real smooth! And I had WAY more control over the process. Here is what I posted on Saturday about my positive experiences with the installation of OS 10.13.4:

https://www.mac-help.com/threads/installation-of-os-10-13-4.224595/