Meesha108
Level 1 (0 points)

Q: iMac 5K with Fusion Drive – two separated disk

Hello, please help me,

 

before sell my iMac 5K Retina (Late 2014) with 1TB Fusion Drive I would erase HDD and then clean install of OS X El Capitan for new owner.

 

I started my iMac with Command+R and after, via disk utility, I choose „Erase” Macintosh HD. But after this I now see two separated disc in left column : Apple SSD and Apple HDD and Untitled below this. It look like that Fusion Drive is separing to two discs See link : http://i67.tinypic.com

 

And after, then I choose install OS X, I must choose either HDD or SSD. But I need Fusion Drive back. Can you help me, please? When I right-click on Untitled disc, do nothing and both disc are OK in Recovery test.

 

Thank you very much for your help and reply and sorry for my English, I’m a begginer.

 

Michael

 

<Link Edited by Host>

iMac with Retina 5K display, OS X El Capitan (10.11.1), null

Posted on Nov 13, 2015 5:46 AM

by Duane,Solvedanswer
Duane Duane
Level 10 (124,018 points)
A:

Not sure if this article has the information you need but it may be useful -> Mac mini (Late 2012 and later), iMac (Late 2012 and later): About Fusion Drive - Apple Support

Posted on Nov 13, 2015 9:13 AM

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Meesha108

Q: iMac 5K with Fusion Drive – two separated disk

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  • by Duane,Solvedanswer

    Duane Duane Nov 13, 2015 9:13 AM in response to Meesha108
    Level 10 (124,018 points)
    Nov 13, 2015 9:13 AM in response to Meesha108

    Not sure if this article has the information you need but it may be useful -> Mac mini (Late 2012 and later), iMac (Late 2012 and later): About Fusion Drive - Apple Support

  • by Meesha108,

    Meesha108 Meesha108 Nov 13, 2015 11:20 AM in response to Duane
    Level 1 (0 points)
    Nov 13, 2015 11:20 AM in response to Duane

    Hello, Duane,

    thank you for your time and reply.

    Yes, I read this post, but it isn't my problem. I haven't a disc icon with red lettering. Maybe exist some easy command in terminal to join discs together? I don't know... I don't understand, why fusion drive is broken   I only erased Macintosh HD ... Any idea?

     

    Thanks.

     

    Michal

  • by Meesha108,

    Meesha108 Meesha108 Nov 14, 2015 2:09 AM in response to Meesha108
    Level 1 (0 points)
    Nov 14, 2015 2:09 AM in response to Meesha108

    Incredible. If I start iMac with Yosemite Install flash disk, I see discs red lettering (under El Capitan not). So I click on first red discs and Fix. And voila! Fusion drive is back! Result : disk utility under El Capitan isn't so good as disk utility under Yosemite ... Thanks. Michal

  • by EVISCERATOR,

    EVISCERATOR EVISCERATOR Nov 14, 2015 11:03 AM in response to Meesha108
    Level 1 (117 points)
    Nov 14, 2015 11:03 AM in response to Meesha108

    Hi Meesha.   Unfortunately disk utility version 15 will not automatically fix a fusion drive that has become separated. The disk utility in Lion thru Yosemite would.  Try booting to internet recovery and after it boots, select disk utilities and click on the SSD and see if it will fix the fusion drive.  Read the instructions near the end of this post, el capitan update wiped my details.

    Best of luck: Tom

    P.S. reply too this post if you need further help.

  • by Meesha108,

    Meesha108 Meesha108 Nov 16, 2015 2:23 AM in response to EVISCERATOR
    Level 1 (0 points)
    Nov 16, 2015 2:23 AM in response to EVISCERATOR

    Hello,

     

    thank you for your interest about my problem. It was already solved! I tried boot from Yosemite flash disc installator and in Disc Utility I fixed red lettering discs. Now is everything OK. I don't know, why El Capitan Disc Utility cannot repair fusion drive. I said that Apple... Now it will already know

    Thanks.

    Michal


    PS: interner recovery not worked. Error -2002 ...

  • by EVISCERATOR,

    EVISCERATOR EVISCERATOR Nov 16, 2015 2:49 AM in response to Meesha108
    Level 1 (117 points)
    Nov 16, 2015 2:49 AM in response to Meesha108

    Glad you got it fixed.  Disk utility in El Capitan will not fix a separated fusion drive but now you can (if you need to for a clean install or erase install) erase the Macintosh HD and it won't seperate your fusion drive so you should not experience this problem in the future.  Just in case you do you can always fix a separated fusion drive with a bootable installer of Yosemite like you just did or boot into internet recovery and use the disk utility there to fix the drive.

     

    Best of luck: Tom

  • by cdavmd,Helpful

    cdavmd cdavmd Nov 28, 2015 11:59 PM in response to EVISCERATOR
    Level 1 (9 points)
    Desktops
    Nov 28, 2015 11:59 PM in response to EVISCERATOR

    For those who have a new iMac and cannot use the Yosemite boot Flash disc solution as outlined above because the newer iMac's with pre-installed El Capitan will not allow previous versions to be installed....I found a solution online that thus far seems to have worked.

     

    My story.....I have an old 2010 iMac that is showing signs of impending Hard Drive Failure.....so I purchased a new iMac 27 inch Retina 5K that came with El Capitan pre-installed.

     

    During my Migration from the old iMac to the new one my User settings, folders, passwords, applications registrations did not come over.  I thus had a new iMac with all my software but nothing else.  So I thought I would try again.

     

    I used the Disc Utility in El Capitan to try and erase the Hardrive and re-install the OS X El Capitan.  It failed....gave me some odd cocoa error....I tried again and  it seemed to work.  I reinstalled El capital only to see that it had not erased all the transferred apps etc.

    Next I went on the web and found articles described how to use Terminal commands to erase the fusion drive.....dumb *** me only succeed in erasing the fusion and ending up with two drives unfused.  Frustration!!  I encountered your posts here and tried by making a Yosemite boot drive but given this mac is new it won't allow the older system to be loaded.

    Several hours of searching later I found the link below.  It suggested using Terminal command to make a group using the HDD and SDD disks.....then to create a new volume.  This worked....at least I think it did.

     

    If any experts out there would let me know if I did anything wrong....

    On my iMac Disk 1 is the SSD and Disk 0 is the HDD

     

    I used the command diskutil cs create GROUPNAME disk# disk#s# to create group called "fusion" from Disk 1 and Disk0s2

    Next: I used- diskutil cs createVolume UUID jhfs+ VOLUMENAME 100% to create a volume called Macintosh HD

     

    At this point I quit terminal and launched Disc Utility.  I ran a repair to make sure it was ok and then re-installed El Capitan.  It seems to have worked.

     

    The only question I have is should I have proceeded with the last steps in the article in which the new Volume is encrypted.  I did not.

     

    I hope this helps any others out there that find themselves in this situation.

    Best

    Carlos

     

    Link to article here: http://www.cnet.com/how-to/how-to-make-a-custom-corestorage-drive-in-os-x/

  • by Meesha108,

    Meesha108 Meesha108 Nov 29, 2015 12:08 AM in response to cdavmd
    Level 1 (0 points)
    Nov 29, 2015 12:08 AM in response to cdavmd

    Hello Carlos,

     

    I knew progress via terminal, but not working for me. Interesting that your iMac can´t loading older OS X Yosemite. Which model of iMac 5K do you have? Late 2015? I have Late 2014 and solved my problem with Yosemite installator via Disk Utility from flash. And how you transfering data? Via migration assistent? It is the best solution by me.

     

    Regards

    Michael

  • by cdavmd,

    cdavmd cdavmd Nov 29, 2015 6:32 AM in response to Meesha108
    Level 1 (9 points)
    Desktops
    Nov 29, 2015 6:32 AM in response to Meesha108

    HI Michel, yes my iMac is late 2015 thus it will not allow older systems than its origin date.  After re-fusing the drives I was successful in re-installing El Capitan.  I then used migration assistant to bring over the information from the old iMac.  It finished late last night and it seems to have worked.  All my files are there and the programs all seem to work.

     

    I hope this helps any others with a similar problem.

    best

    Carlos