Erased OSX Yosemite developer partition not recoverable

Discussion in 'macOS' started by Welshmacjonesy, Oct 20, 2014.

  1. Welshmacjonesy macrumors newbie


    Oct 30, 2005
    I had Yosemite DP on a separate 100gb partition on my MBP, since release of full version i decided to wipe the DP partition and reuse the space but I cannot get the space back. It appears as greyed out space in Disk Utility but I cannot reclaim is as Disk utility will not allow me to repartition or reformat.

    Things I have tried:

    I have run FSCK in single user mode to check the disk.

    Have used Internet recovery partition disk utility and disk utility from a USB installer of Yosemite to try and recover but the partition option is greyed out and I cannot get Disk Utility to format the blank space as when I click on the button to make changes nothing happens.

    I have run disk and partition verification and repair but nothing happens.

    Tried running techtoolpro to check if it can find any issues but no luck.

    I know I can nuke the drive and reformat as I do have a backup but I would rather not have to wait a day while I put over 700gb os apps and software back if anyone can suggest an alternate way of getting back my missing 100gb
  2. Sebb macrumors newbie

    Oct 20, 2014
    I have the same problem. I just created an empty partition on my SSD for "overprovisioning", but i regret it haha. Can't get it back

    I read filevault could be an issue, but it's off in my case

    diskutil list:
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:      GUID_partition_scheme                        *250.1 GB   disk0
       1:                        EFI EFI                     209.7 MB   disk0s1
       2:          Apple_CoreStorage                         223.6 GB   disk0s2
       3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:                  Apple_HFS Macbook HD             *223.2 GB   disk1
                                     Logical Volume on disk0s2
    diskutil cs list:
    CoreStorage logical volume groups (1 found)
    +-- Logical Volume Group CAEAA64D-0EA8-4524-8484-38EB212FDD94
        Name:         Macbook HD
        Status:       Online
        Size:         223560183808 B (223.6 GB)
        Free Space:   0 B (0 B)
        +-< Physical Volume F864F141-2DDF-43E5-AD12-BAB522998794
        |   ----------------------------------------------------
        |   Index:    0
        |   Disk:     disk0s2
        |   Status:   Online
        |   Size:     223560183808 B (223.6 GB)
        +-> Logical Volume Family 2AB54A41-D209-49C0-937F-446D1A6D371A
            Encryption Status:       Unlocked
            Encryption Type:         None
            Conversion Status:       NoConversion
            Conversion Direction:    -none-
            Has Encrypted Extents:   No
            Fully Secure:            No
            Passphrase Required:     No
            +-> Logical Volume FAD2A3C0-1405-43A1-8700-71B60294E735
                Disk:                  disk1
                Status:                Online
                Size (Total):          223207862272 B (223.2 GB)
                Conversion Progress:   -none-
                Revertible:            Yes (no decryption required)
                LV Name:               Macbook HD
                Volume Name:           Macbook HD
                Content Hint:          Apple_HFS
    Can't find the empty space? Disk manager shows this:
    [​IMG] [​IMG]

    Can someone help us?
  3. chrfr macrumors 604

    Jul 11, 2009
    You can't just click in the existing partition and drag it larger? That's how it worked in OS X prior to Yosemite.
  4. Sebb macrumors newbie

    Oct 20, 2014
    That's what I would think. But no, it's not resizable
  5. tywebb13, Oct 21, 2014
    Last edited: Oct 21, 2014

    tywebb13 macrumors 68020

    Apr 21, 2012
    Yes you can.

    The yosemite installation created a core storage logical volume and you can revert it to get partitions back to normal by running these 2 commands in terminal.

    diskutil cs list

    and then

    diskutil coreStorage revert lvUUID

    where lvUUID is the last lvUUID reported by the previous Terminal command.

    Then restart for everything to get back to normal after you have run these commands in Terminal.

    Yes it is. Revert it first. In Sebb's case the revertible lvUUID is FAD2A3C0-1405-43A1-8700-71B60294E735. So in terminal, Sebb can run this, restart the computer and then be able to resize it later with disk utility.

    diskutil coreStorage revert FAD2A3C0-1405-43A1-8700-71B60294E735
  6. Sebb macrumors newbie

    Oct 20, 2014
    Thanks! Will try that later today or tomorrow. After that, how can i get it back to core storage volume again?
  7. tywebb13 macrumors 68020

    Apr 21, 2012
    Well it seems the name you gave it was Macbook HD. So in your case you could get the core storage back with the convert command thus:

    diskutil coreStorage convert "Macbook HD"

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