Missing Fusion Drive

ivantwilliams

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In the process of restoring to factory, I did a 'erase' drive, and then went to reinstall the OS (as you're supposed to).

But, now, the Fusion Drive is missing. Well, it is listed as Fusion Drive 1.02TB, but you can't select it during the OS reinstall, etc.

I can't partition it

I can't run First Aid (does nothing)

I can't mount it

I can only see info.

Weird. Any ideas?

I don't know if I should laugh or cry. This is flipping hilarious...
 

ivantwilliams

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Nov 30, 2014
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IMG_0228.JPG

Yes to both. But, the issue is, when in recovery mode, etc. you don't even see the drive. Hence you can't choose it to proceed.

It is almost as if the drive is 'missing' its partition. Normally, you'd see the drive, and the size of it etc. But, not in this case...

Did you try:

1) Boot in recovery mode (hold cmd +r at startup)

2) Select restore from time machine backup

?
[doublepost=1464783732][/doublepost]...this is what it looks like:
 

keysofanxiety

macrumors G3
Nov 23, 2011
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[doublepost=1464783732][/doublepost]...this is what it looks like:
Hi Afc. When you try and press the Partition option, what error messages do you get? Can you take us through what's happening step-by-step (with pictures if possible) when you try to partition it? Once the disk is partitioned, this will create a mountable volume that you can install OS X to.

Thank you for your patience.
 

ivantwilliams

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Nov 30, 2014
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That's the weird thing, when you press Partition or First Aid, nothing happens, literally.
Only thing that works is 'Info'.

All this because I choose Erase from Disk Utility (and a brief message popped up, "Erase failed", and then the window went away), and then tried the 'Reinstall OS X', option. During that process, I noticed that the drive wouldn't show, tus I couldn't choose it and start the reinstall process...

Thanks

Hi Afc. When you try and press the Partition option, what error messages do you get? Can you take us through what's happening step-by-step (with pictures if possible) when you try to partition it? Once the disk is partitioned, this will create a mountable volume that you can install OS X to.

Thank you for your patience.
 

keysofanxiety

macrumors G3
Nov 23, 2011
9,534
25,266
That's the weird thing, when you press Partition or First Aid, nothing happens, literally.
Only thing that works is 'Info'.

All this because I choose Erase from Disk Utility (and a brief message popped up, "Erase failed", and then the window went away), and then tried the 'Reinstall OS X', option. During that process, I noticed that the drive wouldn't show, tus I couldn't choose it and start the reinstall process...

Thanks
Hi, I'm really sorry for my belated reply. Was testing out the below instructions on a Mac in the office.

Now, as this is a Fusion drive, I'm not sure how it will work ... so rather than diving straight in, we'll go through step-by-step.

Firstly, please open Utilities>Terminal

IMG_5076.JPG


Then type in diskutil list and hit Enter

IMG_5078.JPG


Please can you take a high-quality photograph (so I can see all the writing, like in the above picture) for what you see with the diskutil list command? This will be the deciding factor for the next step.

Thank you again for bearing with me & speak with you shortly!
 

ivantwilliams

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Nov 30, 2014
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No, no, thank YOU for your help...

IMG_0229.JPG


Hi, I'm really sorry for my belated reply. Was testing out the below instructions on a Mac in the office.

Now, as this is a Fusion drive, I'm not sure how it will work ... so rather than diving straight in, we'll go through step-by-step.

Firstly, please open Utilities>Terminal

View attachment 633848

Then type in diskutil list and hit Enter

View attachment 633849

Please can you take a high-quality photograph (so I can see all the writing, like in the above picture) for what you see with the diskutil list command? This will be the deciding factor for the next step.

Thank you again for bearing with me & speak with you shortly!
 

keysofanxiety

macrumors G3
Nov 23, 2011
9,534
25,266
No, no, thank YOU for your help...

View attachment 633850
Right, this is going to be tricky, as each one shows as being a different drive (as I feared). What we can try to do is erase the 24GB SSD, which will split the Fusion drive. Then we can try setup the Fusion drive again through Terminal and see if it's mountable.

Heh, I don't suppose there's an Apple Store local to you?

We'll go through this baby step by baby step to try and avoid any potential problems.

EDIT: Removed instructions -- see alternative instructions below
 
Last edited:

ivantwilliams

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Nov 30, 2014
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There is an Apple shop about 30 miles away, I'd need to book an appointment, etc.
I have a Support call with them in 10 minutes. I'll converse with them first, prior to following the steps below.

This unit is only 14 days old. If this can't be fixed, I'll return it to Best Buy, and then order a built to order unit from Apple, with pure SSD (512GB). I should have done this in the first place.

So, give me about 15 minutes and I'll let you know the outcome. Again, thanks for all your help.

Right, this is going to be tricky, as each one shows as being a different drive (as I feared). What we can try to do is erase the 24GB SSD, which will split the Fusion drive. Then we can try setup the Fusion drive again through Terminal and see if it's mountable.

Heh, I don't suppose there's an Apple Store local to you?

We'll go through this baby step by baby step to try and avoid any potential problems.

First, let's format the 24GB SSD. To do that, please type sudo diskutil eraseDisk JHFS+ TEST /dev/disk0 and press OK. Then once it's done that, close Terminal, and open Disk Utility. Is there a new 24GB volume called 'Test' visible in Disk Utility?
 

keysofanxiety

macrumors G3
Nov 23, 2011
9,534
25,266
[doublepost=1464788985][/doublepost]
There is an Apple shop about 30 miles away, I'd need to book an appointment, etc.
I have a Support call with them in 10 minutes. I'll converse with them first, prior to following the steps below.

This unit is only 14 days old. If this can't be fixed, I'll return it to Best Buy, and then order a built to order unit from Apple, with pure SSD (512GB). I should have done this in the first place.

So, give me about 15 minutes and I'll let you know the outcome. Again, thanks for all your help.
If you don't have much luck with Apple, you can quickly try this (please disregard previous instructions about sudo erase, edited this comment to reflect properly):

Open Terminal. Type in:

diskutil coreStorage create ‘Macintosh HD’ /dev/disk0 /dev/disk1

Once that's done, Terminal will show a 'Core Storage LVG UUID'. It will be alphanumeric, and visible just above 'Finished CoreStorage Operation'. Basically it's the penultimate line visible. Highlight this UUID and copy it.

Then type in diskutil coreStorage createVolume xxxxxx JHFS+ "Macintosh HD" and press Enter.

Where it says 'xxxx', that is where you paste in the Core Storage UUID instead. This should then create a new volume called Macintosh HD which should be visible in Disk Utility.

Then try reinstall OS X to that?

Please quote this/take photos as you go if there are any issues!
 
Last edited:

ivantwilliams

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Nov 30, 2014
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[doublepost=1464788985][/doublepost]

If you don't have much luck with Apple, you can quickly try this (please disregard previous instructions about sudo erase, edited this comment to reflect properly):

Open Terminal. Type in:

diskutil coreStorage create ‘Macintosh HD’ /dev/disk0 /dev/disk1

Once that's done, Terminal will show a 'Core Storage LVG UUID'. It will be alphanumeric, and visible just above 'Finished CoreStorage Operation'. Basically it's the penultimate line visible. Highlight this UUID and copy it.

Then type in diskutil coreStorage createVolume xxxxxx JHFS+ "Macintosh HD" and press Enter.

Where it says 'xxxx', that is where you paste in the Core Storage UUID instead. This should then create a new volume called Macintosh HD which should be visible in Disk Utility.

Then try reinstall OS X to that?

Brilliant, I'll try this in a moment. Apple aren't too willing to try Terminal for some reason.
Almost finished with them. Thanks again.
[doublepost=1464790195][/doublepost]Finally, Apple led me down a path similar to yours!
We entered: diskutil coreStorage createVolume xxxxxx JHFS+ Macintosh HD\ 100%

The drive is now viable, and the OS is reinstalling. As a test, we erased the drive again, and it worked correctly this time. It didn't give an 'error'.

Again, I want to thank you for taking the time to assist me with this, and leading me in the right direction!
If you have PayPal or something similar, send me a PM, and I'll buy you a drink or something :)

[doublepost=1464788985][/doublepost]

If you don't have much luck with Apple, you can quickly try this (please disregard previous instructions about sudo erase, edited this comment to reflect properly):

Open Terminal. Type in:

diskutil coreStorage create ‘Macintosh HD’ /dev/disk0 /dev/disk1

Once that's done, Terminal will show a 'Core Storage LVG UUID'. It will be alphanumeric, and visible just above 'Finished CoreStorage Operation'. Basically it's the penultimate line visible. Highlight this UUID and copy it.

Then type in diskutil coreStorage createVolume xxxxxx JHFS+ "Macintosh HD" and press Enter.

Where it says 'xxxx', that is where you paste in the Core Storage UUID instead. This should then create a new volume called Macintosh HD which should be visible in Disk Utility.

Then try reinstall OS X to that?

Please quote this/take photos as you go if there are any issues!
 
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keysofanxiety

macrumors G3
Nov 23, 2011
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Brilliant, I'll try this in a moment. Apple aren't too willing to try Terminal for some reason.
Almost finished with them. Thanks again.
[doublepost=1464790195][/doublepost]Finally, Apple led me down a path similar to yours!
We entered: diskutil coreStorage createVolume xxxxxx JHFS+ Macintosh HD\ 100%

The drive is now viable, and the OS is reinstalling. As a test, we erased the drive again, and it worked correctly this time. It didn't give an 'error'.

Again, I want to thank you for taking the time to assist me with this, and leading me in the right direction!
If you have PayPal or something similar, send me a PM, and I'll buy you a drink or something :)
No drink necessary! I'm just pleased to hear it's all working now and that Apple got it sorted. :)

Best wishes!
 
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ivantwilliams

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Nov 30, 2014
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All that said, it is a little worrying that pressing, 'Erase' can possibly error out, and thus cause this.
 
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