macOS Sierra - Won't install

So the installer does not want to see my drive. It is greyed out.

What should I do?

How about telling us which Mac you have - year and model? And what version of OS X you're currently running? We can go from there....

oh late 2015 imac
iMac17,1

Thanks for providing your specs. What kind of hard drive do you have installed in the iMac? Fusion? Hard Drive? SSD?

Your 2015 iMac is certainly eligible for Sierra so there must be something else going on which is causing the installer not to see the drive. Try booting to recovery (command + r) and run First Aid on your Macintosh HD. Let us know the result and tell us if there is anything else we should know about your setup.

fusion drive with bootcamp

Did you make a bootable USB installer or are you dong an upgrade?

I always suggest that everyone use the Free DiskMaker (X6 for Sierra) to make a bootable installer. That way you can run diagnosis and repair from the USB drive as well as instal the upgrade.
No matter how you go about the process make sure you have a current backup.
If you make a bootable clone after downloading the Sierra installer you can run it directly from the clone.


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ferrarr said:

Did you make a bootable USB installer or are you dong an upgrade?

Click to expand...

it's an upgrade from el capitan (i'd post a screenshot but the site seemingly doesn't allow me)

edit - the installer says "This disk cannot be used to start up your computer" which is quite clearly false as it currently starts up my computer

How did you create the installer?

If you downloaded macOS Sierra, through the Mac App Store, the official way to get Apple Mac OS versions, then in your Applications folder you will then have the Install macOS Sierra app. There are a few ways to make the USB, I recommend Terminal, but here is a link with the different options to create the USB.

It sounds like you may need to erase you current OS drive to sort things out. Of course, make sure you have a good backup of your Mac OS drive and your Boot Camp drive.

Fusion drives are funny especially with Boot Camp. What I would do, is;

backup Boot Camp
make the drive one partition
Next, I would back up the new single Mac partition
then attempt an erase and install.

To do an Attachment here when you start your message click on Advanced. Then Scroll down to Manage Attachments. Once in there click Add Files and select your picture.

@milomak

A screen shot would certainly help us to figure out what's going on with your installation. Follow the directions given by our Moderator dtravis7 to post a screen shot.

Also.. as noted by member "ferrar" boot camping a fusion drive can lead to problems as the drive might be partitioned off with your Recovery partition at the end of the drive and Boot Camp stuck in the middle. That will not work and probably the reason why Sierra refuses to install. Anyway, provide a screen shot and we can go from there.

Ahh the joy of fusion drives. Seagate they were a con!

PMFJI, but does the issue with Bootcamp apply to SSD in general or only Fusion Drives please?

An SSD, if it is large enough, will have no trouble with BootCamp and depending on the model of your Mac, Windows 10.

Fusion drives in Macs, well the early ones, had only 128GB SSD or so, and the later ones a bare 21GB.

This what the installer looks like when I run it from El Capitan

milomak said:

View attachment 25097

This what the installer looks like when I run it from El Capitan

Click to expand...

Now show us what you see when you "Get Info" on the same drive

I'm just wondering if your Operating System is on "Other" rather than Macintosh HD where it should normally be. Will the installer allow you to install on "other" ?
ferrarr asked about Get Info for Macintosh HD that would be interesting to see.
If you open Disk Utility and just highlight each drive you will get info for each one. Ensure "Owners" are enabled for each one.

The installer will not allow the installation to the Macintosh HD because either that drive is locked or it denotes the entire drive. He has a Boot Camp partition which is rather large (847.16 GB), Recovery (440.4 MB), EFI (73.4 MB) and then it shows his Macintosh HD as being 1.27 TB. Something is not adding up unless his Macintosh HD comprises the entire drive. In that case, where is his OS X partition? All very confusing.

Latest advise from Apple is problems running BootCamp with the 3TB fusion drives at this stage.

At least you have the installer. I can't even download it from the store. Anyone know why? App store simply says "This version of macOS 10.12 cannot be installed on this computer."