I'm having trouble with my Fusion Drive. I was trying to reclaim a 100gb partition that I used BootCamp for. I was unable to delete the BootCamp partition using the Assistant, so I used the Utility Disk to reclaim some of the partitions. I'm now left with 2, but I'm also missing some space from my main Macintosh HD drive (about 200gb) Somehow, it went from 909GB (previous allocated amount) to 700+.

I was following this guide, although I didn't get to any of the resizing section yet. I'm not sure what happened, and was hoping someone could help.

Here's my logs from diskutil list and diskutil cs list:

diskutil list

diskutil cs list

UPDATE: I tried I following the instructions and below and ran across a couple errors.

First, when I tried to mount the physical drives, it said: disk0s2/disk1s2 is a FileVault or Fusion Drive physical volume; use 'disk utility coreStorage list' to find its logical volume, which you can then unlock and mount.

I tried the resizing, and it seems to have started the process, but I left it overnight (roughly 8 hours of run time) and it still wasn't finished with the process. I restarted my computer, and tried running the resizeStack command, and it now says "the target disk is too small for this operation".

When I look up diskutil list, my Macintosh HD drive is still at 773gb, but the deleteme and NO NAME EFI drives are all deleted. I'm just not sure how to reclaim that space.

Any thoughts?

  • I'm not sure if you meant the words "this guide" to be a link or not, but it's not.
    – tubedogg
    Commented Oct 4, 2016 at 16:11
  • @tubedogg Sorry, fixed.
    – Kaidao
    Commented Oct 4, 2016 at 20:45
  • @Kaidao The linked guide (answer) doesn't really fit too your question. If I understand you correctly you want to remove "deleteme" (disk0s5) and the second useless EFI (disk0s4) and expand Macintosh HD (disk3=disk0s2+disk1s2) to 1.02 TB? Right?
    – klanomath
    Commented Oct 4, 2016 at 21:03
  • @klanomath Hi, yes that's correct. Basically revert the HD back to factory settings. I'm okay with wiping data off the volumes, too, as everything is backed up.
    – Kaidao
    Commented Oct 4, 2016 at 21:29
  • @Kaidao I will write an answer in about an hour.
    – klanomath
    Commented Oct 4, 2016 at 21:34

1 Answer 1


To remove the useless second EFI (104.9 MB) and the deleteme partition (104.3 GB) and expand the CoreStorage volume to the full size you have to boot to Internet Recovery Mode.


  • Backup your Mac
  • Detach any external drive (especially your external Time Machine backup drive)
  • Restart to Internet Recovery Mode by pressing alt cmd R at startup. Booting to Recovery Mode is not conducive because the Recovery HD will be moved in one of the steps below. And you can't move a partition used as a boot volume.

    The prerequisites are the latest firmware update installed, either ethernet or WLAN (WPA/WPA2) and a router with DHCP activated.
    On a 50 Mbps-line it takes about 4 min (presenting a small animated globe) to boot into a recovery netboot image which usually is loaded from an Apple/Akamai server.

    I recommend ethernet because it's more reliable. If you are restricted to WIFI and the boot process fails, just restart your Mac until you succeed booting.

    Alternatively you may start from a bootable installer thumb drive (preferably Yosemite or El Capitan) or a thumb drive containing a full system (preferably Yosemite or El Capitan). If you boot to a full system and login as admin you have to prepend sudo to execute special commands like gpt ...!

Remove the partitions 2nd EFI/deleteme and shrink the CoreStorage Volume Group

  • Booted to Internet Recovery Mode open Utilities → Terminal in the menubar and enter: diskutil list to get the disk identifiers and diskutil cs list to get a CoreStorage listing. Below I assume that your main disks have the disk identifiers disk0 (here the HDD)/disk1 (here the SSD) and the CoreStorage Logical Volume disk3. Please modify the commands below according to your environment/findings.

  • First you have to remove the 2nd EFI/deleteme partitions:

    gpt -r show /dev/disk0 #to get an overview

    To remove a partition with gpt the disks (and all related disks like the inherent CoreStorage volume) have to be unmounted - first the CoreStorage Logical Volume and then the physical disks (SSD and HDD):

    diskutil unmountDisk /dev/disk3
    diskutil unmountDisk /dev/disk1
    diskutil unmountDisk /dev/disk0
    gpt remove -i 5 /dev/disk0 #remove the *deleteme* partition
    diskutil unmountDisk /dev/disk3
    diskutil unmountDisk /dev/disk1
    diskutil unmountDisk /dev/disk0
    gpt remove -i 4 /dev/disk0 #remove the *2nd EFI* partition
  • Then you have to first mount and then resize the Logical Volume Group:

    diskutil mount lvUUID #lvUUID: the logical volume UUID

    in your case:

    diskutil mount E6FCA8F6-D6FF-4C0E-976C-1AD2ED107824

    Sometimes you have to mount the PVs first:

    diskutil mount /dev/disk0s2 #mount the physical volume of the CoreStorage Logical Volume Group
    diskutil mount /dev/disk1s2 #mount the physical volume of the CoreStorage Logical Volume Group

    Then resize the whole CoreStorage stack with:

    diskutil cs resizeStack lvUUID size

    in your case (assuming you want to "resize" Macintosh HD to 1024 GB):

    diskutil cs resizeStack E6FCA8F6-D6FF-4C0E-976C-1AD2ED107824 1024g

    If you get Error: -69720: There is not enough free space... use a slightly smaller size like 1023g or 1023500m.

    Now the CoreStorage stack should be expanded to the full size of your Fusion Drive.

After failing to remove a Windows partition with the Boot Camp Assistant parts of the CoreStorage logical structures may be corrupted and the resizeStack command fails with an error. The only possible solution then is to rebuild the Fusion Drive from scratch and restore your system with your current Time Machine backup.

  • Thanks @klanomath I tried this method but ran across a couple errors, please take a look at my edit above and see if you have any suggestions.
    – Kaidao
    Commented Oct 5, 2016 at 14:06
  • Yeah I restarted the computer when I woke up this morning and saw it was still running. This was about 9 hours of operation time since I first started the process; I assumed it was stuck. Could I have damaged the drive? Is there anything I can try before taking it into the Apple Store? What was a bit strange, after I restarted, I booted up the computer and was still able to login to the OS, with all my files still there.
    – Kaidao
    Commented Oct 5, 2016 at 15:45
  • Alright thanks. I do have a backup drive actually with Time Machine already backed up. Should I go into Recovery Mode and back up from there, then retry the process above (resizeStack)?
    – Kaidao
    Commented Oct 5, 2016 at 17:00
  • @Kaidao No, you have to boot to Internet Recovery Mode (alt-cmd-R while booting), completely remove the CoreStorage LVG with diskutil cs delete 889AD... (< use the complete UUID of the Logical Volume Group here), recreate your Fusion drive and restore the TM backup.
    – klanomath
    Commented Oct 5, 2016 at 17:05
  • I see. So after I remove the CoreStorage LVG, do I run 'diskutil cs resizeStack lvUUID 1024g' to rebuild the Fusion drive? Thanks for your help!
    – Kaidao
    Commented Oct 5, 2016 at 17:36

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