Factory reset

[sheedee]

Hello;





Today I tried to factory reset my iMac so I went into disk utilities and went to the option to erase the Macintosh HD but after I got a message saying that the operation had failed...so then I tried the first aid option to fix any possible errors...afterwards it said that the operation was completed so I assume that the disk errors were fixed.


So then afterwards I went to the option to install a fresh copy of the OS High Sierra...but this was not possible because the Macintosh HD could not be found!...


I have no idea what I am doing or what went wrong...


I have attached some photos that I took with my phone of the iMac screen...I have no idea what I am looking at or how to fix the problem.





Can anyone please tell me how to solve this problem?..








Thanks.

 

[Cory Cooper]

Hello and welcome.

Try erasing the one I have highlighted with the arrow:

See if that works.

Also, are you performing these steps when started up from macOS Recovery?

C

 

[sheedee]

I erased the one that you told me...and then somehow I created an other volume and it seemed to have worked and I proceeded to install the fresh copy of Sierra and that all went fine...with one problem though...when I chose to update I get a message that there is not enough space for the updates to be installed!...there is only 9GB of disk space left and 11GB is needed for the update to be installed.

The problem is that the OS is installed on a volume that only has 27GB of total capacity...the OS should have been installed onto the 1TB container disk!...so now how do I solve this...I probably will have to go back to disk utilities and repeat everything again right?...but then choose the right volume {or container}?


Please some advise

 

[MartyByrde]

It seems you have a Fusion Drive on your machine, and that volume he pointed to is the SSD portion, which typically does not take up much space. In fact, the device entitled "APPLE SSD SM0032" is the SSD "piece", and the size is 28 gig, which should be more than enough to have just the OS High Sierra installed on it.

If you first point disk Utility to Erase and Format the Volume entitled "APPLE HDD ST1000", and then again for the Volume entitled "APPLE SSD SM0032", and then point to the volume entitled "APPLE HDD ST1000" when you do the clean, fresh installation of High Sierra, it seems that would work, and that the installation process would be "smart enough" to know what system-related files would be installed on the SDD Volume.

All of that, though, is a guess on my part, as I have never dealt with a Fusion Drive. Maybe Cory (or someone else) has more in depth knowledge about that.

 

[MartyByrde]

By the way, saw this:

Should you upgrade your Fusion Drive iMac to macOS High Sierra?

Users are concerned with Apple new APFS format.

www.macworld.com

One would expect by now that the last version of High Sierra, OS 10.13.6, resolved this "APFS/Fusion Drive" issue.

 

[sheedee]

As I said before the OS is currently installed (and working) only its installed on a very small volume of only 27GB
and the idea is to get it installed on a bigger volume (1TB container...as it was by default when I bought the computer)
Only how can that be done considering the current state of the situation?...I would say I would try MartyBryde,s suggestion...but before I attempt on doing that, here are some screens to show how things look at the moment after all that I have done.
Again, the whole purpose is to install the OS (again) ...but on the 1TB part of the main container...and how to do that.



Suggestions are welcome.

 

[MartyByrde]

Sorry I misunderstood.

But why do you want to install High Sierra on the slower 1 TB HDD? From what I understand, it is a 5400 rpm drive, and if High Sierra is (and can be) installed on it (and wiped from the SSD), your iMac will boot up slower (and there could be other tasks that will be slower).

 

[sheedee]

The reason I want to install Sierra on the 1TB HDD is because that is where it was originally installed on when I bought it (at least that's what I think...I could be wrong though...I am no expert) and the other reason I want to install it on the 1TBHDD is because there is obviously much more disk space on there which makes it easier to install updates and software and everything else.

Bare in mind that for me all this is very confusing...containers and different volumes etc.

It might very well be the case that the volume where the OS is currently installed on (the one that I created and named Macintosh HD) that its properly installed there and does not have to be removed and installed on a bigger volume(but I still don't think so because like I said before I tried installing updates and it did not allow it because it said there was not enough disk space.). Which suggests again that the OS must be installed on a bigger volume than the one that its currently on which is this one:

So my question still remains unanswered and still the same...how to remove or erase (if this really has to be erased) the above shown volume and then create a bigger volume...and then reinstall the OS on that bigger volume?

 

[MartyByrde]

Again, please understand that I am certainly no expert on Fusion Drives. But I suspect, before you created the device entitled Macintosh SD, that it was originally a Fusion Drive.

Look at this link:

About Fusion Drive, a storage option for some Mac computers

Fusion Drive combines the performance of Flash storage with the capacity of a hard drive.

support.apple.com

.

Note first where it says:

"Fusion Drive manages all of this automatically in the background. And it comes already set up, so you don't have to do anything to make it happen."

Hence, that is why I said that originally, it was a "true" Fusion Drive.

Now, where it says:

"Learn what to do if your Fusion Drive appears as two drives instead of one in the Finder."

Clicking on that link beings this up:

How to fix a split Fusion Drive - Apple Support

If your Fusion Drive appears as two drives instead of one in the Finder, it's no longer working as a Fusion Drive. Here's how to fix it.

support.apple.com

I'm thinking you have a split Fusion Drive, and thus why you are having issues.

And then there is this:

"What is a Fusion Drive

A Fusion Drive is two separate drives ‘fused’ together. It contains a Serial ATA drive (that’s a regular hard drive with a spinning plate inside) and a solid-state drive.

MacOS places the more frequently accessed files - including the OS itself, and apps - on the flash storage part of the drive so that they are always quick to obtain, while less frequently used data is stored on the hard drive."

So, it seems that all of the pieces belonging to the OS are on the Fusion Drive. Also, your iMac "learns" from your actions and moves "items" to the Flash Storage part of the drive. And I suspect the OS correctly manages all this.

So, first check to determine if, via your actions, the device is no longer a "true" Fusion Drive.

Secondly, what is currently on the larger, 1 TB HDD?