Philfromnv

Q: Fusion Drive  4TB + SSD m4 512 Go DEAD can't reformat

Hello,

 

I have an iMac 27 late 2010 i5 3.6 with 16 Go of RAM running 10.8.3

 

For Christmas, I received a M4 SSD 512 Go and decided to replace the 2TB in my iMac with a 4TB and create a Fusion Drive.

 

The operation worked beautifully and my iMac became incredibly fast, which was the goal.

 

Yesterday, the iMac did not start and I got the white screen with the spinning wheel. After reading about zapping the pram and Vram, nothing worked.

 

I booted from an external hard drive with Mac os X 10.8.2 and ran Disk Util to check the drive. I got a lot of red lines in the report and got the error Disk Utility can't repair this disk. back , reformat and restore.

 

I was able to copy some of the files on the drive and decided to reformat the drive.

 

Everytime I try to reformat the drive (4.4tB Fusion Drive) the mac shuts down and restarts.

 

I tried to un fuse the fusion drive and I get the same result.  the screen goes black, the computer restarts and displays that the mac encountered a problem and had to restart.

when I type the commande in terminal diskutil cs file, I see the logical volume group.

 

When I do a diskutil cs Delete Volume xxxxxx xxxx xxx x x x x x x x

started CoreStorage operation on disk 2 iMac

Unmounting disk2

Removing Logical Volume from Logical Volume Group

...

then the mac shuts down and restarts.

 

it took me 2 hours to crack the beast open to perform the disk implant last  christmas and it was scary. I thought I would never manage to close it properly.

 

I understand that this operation voided the warranty (i have the Apple Care for 3 years).

 

Any help greatly appreciated.

 

Thanks

 

Phil

iMac, OS X Mountain Lion (10.8.3), iMac 27 late 2010 i5 3.6 with 16 Go

Posted on May 10, 2013 7:29 PM

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Q: Fusion Drive  4TB + SSD m4 512 Go DEAD can't reformat

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  • by RRFS,

    RRFS RRFS May 11, 2013 12:11 AM in response to Philfromnv
    Level 5 (4,490 points)
    May 11, 2013 12:11 AM in response to Philfromnv

    Unless you are lucky and find a loose connection inside you probably lost the SSD.

  • by maxintosh pro,

    maxintosh pro maxintosh pro May 11, 2013 3:18 AM in response to Philfromnv
    Level 1 (65 points)
    May 11, 2013 3:18 AM in response to Philfromnv

    Fushion drives are very good; however they do put a great deal of load on the SSD. Writing to it, then reading off it to write to the HDD - it is quite a lot for the SSD to do. My own opinion is that this should have been fine and worked perfectly.

     

    Because of the above, I think there is something that has been JIGGLED or MOVED ABOUT that has done this. I doubt your SSD would have failed in such short time. What is the warenty on your SSD? You may still be able to return this to Crucial or the retailer under the fact that it is no longer functioning correctly.

     

    As you have voided the warenty already, you may as well crack it open again and have a go at trouble shooting where the broken/damaged connection is. It is most likely to be in the SSD connection to the main board; however, this error could have originated in the HDD connection to the main board.

     

    There is little else you can do. Apple Genius Bars will laugh at you and take all of your money for something very simple.

  • by Philfromnv,

    Philfromnv Philfromnv May 11, 2013 2:14 PM in response to maxintosh pro
    Level 1 (0 points)
    May 11, 2013 2:14 PM in response to maxintosh pro

    Thanks for your answers.

     

    I still don't know if it was the SSD or the HD that was faulty but I found a solution via this post

     

    https://discussions.apple.com/message/21492423#21492423

     

     

    @Topher : It did not work, and it failed with POSIX errors similar to the zeroDisk message I posted above.

     

    However, While I was unable to "cleanly" solve my problem, I managed to reset everything by booting in single-user mode from an external hard drive (with cmd-S) and overwriting the disk directly with

     

    cat /dev/random > /dev/disk0

    cat /dev/random > /dev/disk1

    Then I rebooted and I could reformat the drives (actually, I created another fusion drive using these directives).

     

    I was able to reformat the drives as a Fusion Drive. My time Machine backup was only a week old but it worked perfectly. I was able to add the rest via my Backblaze subscription.

     

    Don't know how long the Fusion drive will last but I am prepared with my backups in case it happens.

     

    Phil

  • by asupergav,

    asupergav asupergav Jun 4, 2013 4:10 AM in response to Philfromnv
    Level 1 (0 points)
    Jun 4, 2013 4:10 AM in response to Philfromnv

    Your're a braver man than me, Phil.I'd never tinker inside a computer that was still under warranty. Your sentence:

     

    "The operation worked beautifully and my iMac became incredibly fast, which was the goal."

     

    brings to mind the old surgeon's maxim: "The operation was a success, but the patient died." Or in your case. the patient was resuscitated.