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harryhood

macrumors regular
Original poster
Mar 15, 2006
240
0
My Fusiondrive failed. It won't restore or rewrite. I need to install a new drive on this computer ASAP.

IIRC a while back there were authentication issues with installing SSDs. I'd like to install a minimum 3tb, fastest / best combo available today. I know it's a pain to remove the screen, but I'm not worried about that. I'm only worried about SSD compatibility and the details for that.

Wondering if I'm going to need to jump through a lot of hoops and if anyone can recommend a drive/combo. I'd even be down to do a dual drive, main SSD + HDD if thats an option for my iMac model.

I have a: iMac Intel 27" 3.4 GHz (Core i7, Late 2012)

Any recommendations for drives (the best available today), guides etc are greatly appreciated!!
 
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The Fusion drive is created from a separate SSD and a separate hard disk linked together by the operating system software, it is not a single unit. While the hard disk is pretty standard, the SSD is a blade type which is a bit more difficult to find. But first...

If you boot from the recovery partition and enter Disk Utility from there, the system may attempt to fix the problem for you.

Otherwise, you might want to boot from an external drive and have Disk Utility take a look at what you have going on. You will easily find (Google) instructions for unlinking the Fusion drives so you can figure out which one, if either, is defective. That will let you know how to proceed next...

If you are still under warranty ... you may want to let the Apple Genius figure it out for you. Opening these computers is not easy or straightforward, even if you are experienced.
 
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I'm not too worried about opening it up..

But I can't figure out how to distinguish between the two drives in disk utility. Right now I'm running from an external.

It won't even let me restore the HDD or do anything. The partition part only shows one and everything is grayed out.

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You will only see a single "Fusion" drive in Disk Utility until you "un-Fusion" them. If you follow one of the DIY Fusion articles, you will see where you can use Terminal to run the "diskutil list" and "diskutil cs list" commands to see the core volumes in your system.

Until the disks are logically separated in terminal, they are considered a single volume and that is what you will see in OS X. You can't manipulate or view the components of the Fusion drive separately ... it is a single logical drive.

As mentioned, if you run Disk Utility from the recovery partition, you may be able to let the system fix the Fusion drive automatically, depending on the nature of the problem. You need to at least try this just to see if it identifies that there is a Fusion drive problem.

You may want to post exactly what error messages, or operations you were unable to perform, that indicates that your Fusion drive is damaged. Then someone here may be able to suggest less intensive repair solutions before you attempt to "break and rebuild" the Fusion corestorage logical drive.

Again, if you have Apple Care on this iMac ... this may be a good time to use it. :)
 
If you're comfortable opening up the iMac, then go for it. I haven't yet opened up one of the new 2012/2013 super thin models, but I've opened up almost every other iMac model and they were not that difficult for the technically inclined or experienced.

Like hfg says, you need to identify which drive is bad and either replace it or remove it. If you replace it, you can rebuild the fusion drive in your machine. If you remove it, then you can run off just the SSD or the HDD, whichever it still in good shape.

If you have AppleCare, definitely use it and take it to an Apple store. If you don't have AppleCare you can still take it to an Apple store and they might be able to tell you what's wrong; of course, having them fix it outside of AppleCare will be significant dollars.
 
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