Installation question: MacBook Air 13.3 Retina 2018 Model A1932

[08154711]

Hello everybody,

I need some help in regards to reinstalling MacOS Mojave on the MacBook stated in the thread subject line. I hope I gave all the basic details needed.

Now I don't know much about OS's for the general public (Windows, Apple/Macintosh, etc.). I work on what you might call 'supercomputers', yes, the ones behind the scenes that allow us all to do what we are doing right now. So I am definitely a Unix person, and after this slim and sophisticated OS, I slip right into database management.

I will probably need some step-by-step (baby steps?) instructions.

That being said, I received this MacBook. It has not been used in a long time (probably over 1 year), the battery was dead. I was able to get it charging again after several attempts over several days. As there is no indicator light (not in the OEM charger nor the cable), I found out when it started on it's own, with a very loud startup sound. Yeah!

It displays a question mark on the screen and a website address at the bottom, support.apple.com I have to say, the instructions on Apple's website were simple and straightforward.

I got to the disk utility and am ready to reinstall the OS Mojave the MacBook came with, apparently the installation files are somewhere on a hard-drive.

So here is my first question (and yes, picture below/attached): When trying to install, it asks to which drive, it shows 2, one labeled Macintosh HD, the other one Update.

Does it have 2 drives? The main spec sheet from Apple said it has a single 256 SSD drive.

Would someone please explain to me why there are 2 drives? Is one a partition on possible a larger drive? Or is it a ghost drive that used to be attached and something needs to be reset/deleted to make it disappear?

Thank you in advance for any valuable input.

 

[IWT]

That being said, I received this MacBook. It has not been used in a long time (probably over 1 year),

Firstly, a warm welcome to Mac-Forums. Thank you for your post.

With regards to the above, has the previous owner disassociated their Apple ID from that Mac? This is important because, if not, you will have problems.

It displays a question mark on the screen and a website address at the bottom

This may mean that your startup disk is no longer available or doesn't contain a working Mac operating system.

I got to the disk utility and am ready to reinstall the OS Mojave the MacBook came with, apparently the installation files are somewhere on a hard-drive.

Does it have 2 drives? The main spec sheet from Apple said it has a single 256 SSD drive.

There shouldn't be two drives and you can't use or count on installation files "somewhere".

I think that you need to wipe both drives and start afresh using Internet Recovery:

Reinstall macOS

You can reinstall macOS on your Mac while keeping your files and user settings intact.

support.apple.com

I realise this is a big problem for anyone unfamiliar with the Mac, but I hope my remarks may assist you.

Ian

 

[08154711]

Thank you for your quick reply. It's not really a big problem, just need some pointers how to to it. After all, once it is done, I probably will never do it again (wishful thinking). I appreciate your patience.

I followed the instructions on Apple's website. So yes, the previous Apple ID was removed, the Google drive disconnected, all other services stopped, histories deleted.

Then I reset the NVRAM.

Then started it with the <Command> and <R> keys pressed. It went to the utility windows in which I selected <Disk utility>. I then selected each of the 2 drives and erased them. Went through with no issues.

As said, now I see 2 hard drives. I selected the Macintosh HD and it did install Mojave. It then did some updates and the MacBook worked fine. The <System Preferences/Updates> now tell me that I can download and update to Big Sur.

But, I want to know what the deal is with these 2 drives, especially the one called <Update>. The displayed size appears to be identical. I would prefer to start with a clean install.

I even tried to 'unmount' the 2nd one (called Update), thinking it might be a ghost drive. It still shows up, just displayed in light grey, sort of not available but there.

Is there an additional hard reset or similar I have to do before installing the OS?

 

[MacInWin]

The are probably NOT two drives, but two Volumes on the same drive. In Disk Utility, on the top bar, click on "View" and select "Show all devices." What you will see then should look something like this:

The hardware is the top on the left panel, in my case "APPLE SSD AP1024R Media." Indented from that is a Container (as Apple terms it, and in the Container is a Volume (as Apple calls it) named Macintosh HD and another under that with Macintosh HD greyed out and then one at that same level named Data. The greyed out Volume contains the system and is read only and encrypted to keep anyone from meddling with it. The Data Volume has user data and some configuration information and applications that are installed by the user(s) on the system who have authority to do so. I am running Monterey, so your image may be slightly different because as I recall Apple called it Macintosh HD and Macintosh - Data in older versions of the OS.

The system bonds the two Volumes into one logical drive for the user, named Macintosh HD.

OK, with that background, how the APFS file structure from Apple works is that all Volumes in a Container share the free space allocated to the Container when it is formatted. So, in my example, both Macintosh HD (greyed out) and Data can both claim the 408GB free space as available. But when either of them takes any of that free space, both would have the space available reduced. So, in my example, if I create a new 8GB file in my own directory in Data, then BOTH would be reduced in free space to 400GB.

So, what I think you are seeing are two Volumes on the SSD in the same Container. If there is nothing in one of them, you can use Disk Utility to just delete that Volume and it won't affect the other.

Hope that helps some.

 

[08154711]

Thank you MacINWin, I am sure you know what you are talking about, but even after reading it slowly over and over again, I am not getting it. And that is okay.

Hope this helps: picture of how my current Disk utility looks like:



When I click on the 'Update' drive (under 'Container disk2') and select <Erase>, it does so, says it did so, and then the screen still looks like this. Am I doing something wrong, or not something that should be done? How can I get rid of the 'Update' volume?

Did I get it right? The APPLE SSD 256 is the solely drive (256 GB I assume). The 'MacIntosh HD' is the main drive and the 'Update' one is a 'Volume"?

So would this comparable to partitions on PC drives?

Thank you for your patience.

 

[08154711]

Look at this, I selected the volume 'Update', and when I clicked on the "-" under Volume in the top menu, it asks me if I wanted to delete it.

Is this what need to be done? Then it will only show the Macintosh HD? And the wording 'Container disk2' might change to '1'?

Don't worry, I wont do anything before verified.

 

[MacInWin]

No, Container disk2 will remain Container disk2. As for deleting Update, is there anything ON Update that you want? If so, you should copy it off to someplace safe before deleting Update, or just leave it there. As I said in my earlier post, the way APFS manages the drive is that it creates Containers on the drive (sort of like the old technology Partitions), then within the Container, it creates Volumes that share the Container space. So, in your images, Macintosh HD and Update share whatever space is allocated to Container disk2. From the bar below the popup I see that only 20kb is shown as Used on Update, so I suspect it is empty. When it says Other Volumes are taking up 1.21 GB, that is probably on Macintosh HD, and would be the Operating system components, although that does seem to be too small to store the entire OS. On my Monterey system, for example. Macintosh HD has about 16GB Used.

You said you wanted to do a "clean install" earlier. So what I would do at this point is select the highest level, where it says, "APPLE SSD AP0256M Media" and then select Partition, and I think it will offer to format the internal drive for you. Use APFS and GUID for the details. It should ask for a name, give it Macintosh HD and if it asks, full drive access (I'm not sure if it asks or not, or if it shows a number or not. What you want to do is to format the entire drive and let it create a new Container with Macintosh HD as a Volume. Then in the Recovery Panel (with the four options for you), select "Install..." and let it do its thing. At the end, it should either return to the Recovery panel or offer to reboot. In any case, reboot, it should now boot from the internal drive with the newly installed OS. It asks some questions to set up basics and then you get to create your account on the Mac. Once that is done and a bit of housekeeping (login to iCloud, etc), you should be good to go.

Here is the top link at Apple for how it all works. You can follow some of the links to where you want to go:
How to reinstall macOS
That Mac is an Intel Mac, so follow those links.

 

[08154711]

I select the main level ( APPLE SSD AP0256M Media) and selected 'Partition'. There is no offer to format, it asks about partitioning and/or adding another volume. Which way do I go now? Or do I have to go back and erase/delete a partition first?

 

[MacInWin]

You want to Partition at that point. It will totally erase the drive and create one single partition and one Container on the partition and then 1 or 2 volumes inside the Container will be created when you install the OS. Once more, doing that will totally wipe out the drive, but you said you wanted a clean install, so that is how to do it.

 

[08154711]

Well, that resulted in no changes at all, it sill looks the same.

I selected <Partition>, it displayed the harddrive with the 2 volumes (MacintoshHD/Update), but the <Apply> button was greyed out (not selectable).

I had to click on the +/_ button on the left to initiate action, then chose <Apply>, it said it does it but no partitions will be erased. And now everything is exactly like before.

Don't I have to delete the partitions first? After all, this is about getting rid of the one labeled <Update>.

 

[MacInWin]

After all, this is about getting rid of the one labeled <Update>.

OK, I'm confused now. In post #3 you said:

I would prefer to start with a clean install.

A clean install generally means to erase the drive completely and start all over fresh. But now you say you just want to get rid of "Update." Which is it? If all you want to do is get rid of "Update," you can do that in DU by selecting it and then choosing it by clicking on it, then right click (CTRL-click), and select Delete Volume to make it go away. If you really want a "clean" install, then go ahead and partition the entire drive while booted from the external drive with the installer on it, then go back to the Recovery panel and do the installation.

 

[08154711]

Okay, it looks like I figured it out myself. Unless something changes, it works just fine.

Hhere is how to do it simple:

1.) Click on each of the partitions/volumes, whatever one calls it. In my case: Macintosh HD and Update
2.) Once one is selected, click on the '-' above the <Volume> in the left top corner. This deletes the partition/volume.
3.) Click on the internal drive, in my case APPLE SSD AP0256M Media. Click on partition, by default it creates one as big as the harddrive. I labeled it Macintosh HD again.
4. Go back to the Disk Utility, it now shows only 1 drive (labeled Macintosh HD). Install OS.

Once done I got all the updates which ended with the macOS 12 Monterey. Pretty nice that it updgraded to the most current OS.

Sorry about the blurred pictures, it must have something to do with the theme macOS 12 is using, as everything else is the same (placement of MacBook, lighting, camera etc.).

 

[MacInWin]

Glad you got it done. Steps 1 and 2 of your process are not really necessary, as Step 3 does the same thing as part of the partitioning. Neither of them should have taken very long, so you didn't waste much time on the unnecessary stuff. The big job was partitioning and reinstalling the OS.