Cannot delete partition

Question

I went to use boot camp to install windows, after partitioning and on the windows installation screen to select the boot camp partition, it said it Couldn’t find a partition. I selected the 300GB partition that was made, and selected erase, then format, then new. Still could not install so I exited the installer. When I ran boot camp assistant to erase the partition, it would not. I have been on the phone with AppleCare twice now and was just escalated to an engineer but I thought I might post here just Incase. I was brave enough to run the commands recommended here: http://www.pervasivecode.com/blog/2016/05/23/fixing-a-mac-fusion-drive-that-disk -utility-cant-erase/While that did erase my fusion drive, that **** partition is STILL THERE! I’m totally stumped, and annoyed as my iMac now sits here restoring from my time machine backup.

Loner T · Accepted Answer

You have two different issues.During the Windows installation, there was an external storage unit attached, which caused Windows installer to create the EFI &#x27;NO NAME&#x27;. Please post the Terminal session output and stop if you see any errors.Run the following commandsdiskutil eraseVolume jhfs+ BC1 disk0s4diskutil eraseVolume jhfs+ BC2 disk0s5diskutil mergePartitions jhfs+ BCMP disk0s4 disk0s5diskutil listIf diskutil list does not show disk0s5, then run diskutil eraseVolume fat32 BOOTCAMP disk0s4run BCA and click on Remove/RestoreYour CS volume has the 2TB HDD at index 0, which causes the BCA to create more issues. After you finish the cleanup, i suggest you rebuild the CS &#x27;Fusion&#x27; volume with the 121GB disk at index 0 and the HDD at index 1. This will help lessen the heartburn during partitioning.Your LaCie should be disconnected during the installation of Windows. It can be connected once the installation is complete. You should also run SMC/NVRAM Reset before the next attempt at Windows installation.

theBIGone2087 · Answer

Last login: Thu Nov  9 19:36:42 on ttys000Erics-iMac:~ ericpfister$ diskutil eraseVolume jhfs+ BC1 disk0s4Started erase on disk0s4 NO NAMEUnmounting diskErasingInitialized /dev/rdisk0s4 as a 100 MB case-insensitive HFS Plus volume with a 512k journalMounting diskFinished erase on disk0s4 BC1Erics-iMac:~ ericpfister$ diskutil eraseVolume BC2 disk0s5Usage:  diskutil eraseVolume format name MountPoint|DiskIdentifier|DeviceNodeCompletely erase a disk (partition or whole), laying down a new file systemvolume.  Ownership of the affected disk is required.  Format is the specificfile system personality name (or alias) you want to erase it as (JHFS+, etc.).Name is the (new) volume name (subject to file system naming restrictions), orcan be specified as %noformat% to skip initialization (to skip newfs). Youcannot erase the boot volume.  A format of "Free Space" will cause removalof the partition.Example: diskutil eraseVolume JHFS+ UntitledHFS /Volumes/SomeDiskErics-iMac:~ ericpfister$ diskutil eraseVolume jhfs+ BC2 disk0s5Started erase on disk0s5 untitledUnmounting diskErasingInitialized /dev/rdisk0s5 as a 279 GB case-insensitive HFS Plus volume with a 24576k journalMounting diskFinished erase on disk0s5 BC2Erics-iMac:~ ericpfister$ diskutil mergePartitions jhfs+ BCMP disk0s4 disk0s5Merging partitions into a new partition     Start partition: disk0s4 BC1     Finish partition: disk0s5 BC2Started partitioning on disk0Merging partitionsWaiting for partitions to activateGrowing diskFinished partitioning on disk0/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *2.0 TB     disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2:          Apple_CoreStorage Macintosh HD            1.7 TB     disk0s2   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3   4:                  Apple_HFS BC1                     300.1 GB   disk0s4Erics-iMac:~ ericpfister$ diskutil list/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *2.0 TB     disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2:          Apple_CoreStorage Macintosh HD            1.7 TB     disk0s2   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3   4:                  Apple_HFS BC1                     300.1 GB   disk0s4/dev/disk1 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *121.3 GB   disk1   1:                        EFI EFI                     209.7 MB   disk1s1   2:          Apple_CoreStorage Macintosh HD            121.0 GB   disk1s2   3:                 Apple_Boot Boot OS X               134.2 MB   disk1s3/dev/disk2 (internal, virtual):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:                  Apple_HFS Macintosh HD           +1.8 TB     disk2                                 Logical Volume on disk0s2, disk1s2                                 CC8328F8-A3AD-4B34-8388-DFF5CD0611D4                                 Unencrypted Fusion DriveErics-iMac:~ ericpfister$ diskutil eraseVolume fat32 BOOTCAMP disk0s4Started erase on disk0s4 BC1Unmounting diskErasing4096 bytes per physical sector/dev/rdisk0s4: 585922944 sectors in 9155046 FAT32 clusters (32768 bytes/cluster)bps&#x3D;512 spc&#x3D;64 res&#x3D;32 nft&#x3D;2 mid&#x3D;0xf8 spt&#x3D;32 hds&#x3D;255 hid&#x3D;3320700928 drv&#x3D;0x80 bsec&#x3D;586066056 bspf&#x3D;71528 rdcl&#x3D;2 infs&#x3D;1 bkbs&#x3D;6Mounting diskFinished erase on disk0s4 BOOTCAMPErics-iMac:~ ericpfister$I ran the BCA and sure enough, it restored the partition! NO more random 300GB partition I can&#x27;t do anything with. I&#x27;ll reset SMC and NVRAM... how exactly do I &#x27;rebuild&#x27; my fusion drive to reset the indexes? Thank you for ALL the help!!!

Kappy · Answer

This should return your drive to a single volume using all the space on the drive:Install Sierra or El Capitan from Scratch     Backup if possible before continuing.Restart the computer. Immediately after the chime hold down the CommandandRkeys until the Apple logo appears. When the Utility Menu appears:Select Disk Utility from the Utility Menu and click on Continue button.When Disk Utility loads select the drive (out-dented entry) from the Device list.Click on the Erase icon in Disk Utility&#x27;s main window. A panel will drop down.Set the Format type to Mac OS Extended (Journaled.)Click on the Apply button, then wait for the Done button to activate and click on it.Quit Disk Utility and return to the Utility Menu.Select Reinstall OS X and click on the Continue button.

Loner T · Answer

You will need a Time Machine backup to rebuild your CS. Before we dive into that, try to re-run BCA and see if you can install Windows. Do not connect any external storage and/or hubs.Based on what you have posted, Apple may have fixed a long-standing &#x27;bug&#x27; in BCA. Please choose the BC partition to be larger than 120GB.

Loner T · Answer

From Terminal, post the output of diskutil listdiskutil cs list diskutil apfs list What is the year/model of your Mac?

Loner T · Answer

You can run the first part when normally booted. Once you run the SMC and NVRAM reset, we should test BCA before we venture into the Fusion rebuild.

theBIGone2087 · Answer

Doesnt work. That’s was the first thing I tried. When I select the fusion drive, the erase option is greyed out. I can erase the two partitions, but that doesn’t remove them. The fusion drive itself does not allow me to erase.

Kappy · Answer

There is a fix for this but I do not know the Terminal commands needed. If you are fortunate another user, Loner T, will come along with the fix. Fusion drives have certain limitations with respect to partitions and Boot Camp.

theBIGone2087 · Answer

Erics-iMac:~ ericpfister$ diskutil list/dev/disk0 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *2.0 TB     disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2:          Apple_CoreStorage Macintosh HD            1.7 TB     disk0s2   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3   4:                        EFI NO NAME                 104.9 MB   disk0s4   5:                  Apple_HFS untitled                300.0 GB   disk0s5/dev/disk1 (internal, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *121.3 GB   disk1   1:                        EFI EFI                     209.7 MB   disk1s1   2:          Apple_CoreStorage Macintosh HD            121.0 GB   disk1s2   3:                 Apple_Boot Boot OS X               134.2 MB   disk1s3/dev/disk2 (internal, virtual):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:                  Apple_HFS Macintosh HD           +1.8 TB     disk2                                 Logical Volume on disk0s2, disk1s2                                 CC8328F8-A3AD-4B34-8388-DFF5CD0611D4                                 Unencrypted Fusion Drive/dev/disk3 (external, physical):   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *3.0 TB     disk3   1:                        EFI EFI                     209.7 MB   disk3s1   2:                  Apple_HFS LaCie                   1.0 TB     disk3s2   3:                  Apple_HFS Time Machine            2.0 TB     disk3s3Erics-iMac:~ ericpfister$ diskutil cs listCoreStorage logical volume groups (1 found)|+-- Logical Volume Group 7441BCB5-358B-4284-B124-4D8BDF84F079    &#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;    Name:         Macintosh HD    Status:       Online    Size:         1810690760704 B (1.8 TB)    Free Space:   16384 B (16.4 KB)    |    +-&lt; Physical Volume FE1AD59B-FC99-4A6D-936A-0F43F60D960B    |   ----------------------------------------------------    |   Index:    0    |   Disk:     disk0s2    |   Status:   Online    |   Size:     1689701908480 B (1.7 TB)    |    +-&lt; Physical Volume 0AF1B37C-A1BC-48DC-948F-30D24A7BF626    |   ----------------------------------------------------    |   Index:    1    |   Disk:     disk1s2    |   Status:   Online    |   Size:     120988852224 B (121.0 GB)    |    +-&gt; Logical Volume Family 3D7AE8CB-A4BD-4853-8D3F-2C43E91AE6B4        ----------------------------------------------------------        Encryption Type:         None        |        +-&gt; Logical Volume CC8328F8-A3AD-4B34-8388-DFF5CD0611D4            ---------------------------------------------------            Disk:                  disk2            Status:                Online            Size (Total):          1804835487744 B (1.8 TB)            Revertible:            No            LV Name:               Macintosh HD            Volume Name:           Macintosh HD            Content Hint:          Apple_HFS            LVG Type:              Fusion, SparseErics-iMac:~ ericpfister$ diskutil apfs listNo APFS Containers foundMy iMac is a Late 2015 27" 5k, 4GHz i7, 24GB RAM, Radeon R9 M395X. macOS 10.13.1This is what Disk Utility Shows:

Kappy · Answer

I have made a request for help to Loner T. When he gets it I&#x27;m sure he&#x27;ll come along and help you.

theBIGone2087 · Answer

Also, not sure if this helps or not, but when I run Boot Camp assistant, it only shows the 300GB partition as what can be used, but doesn&#x27;t allow the partition to be formatted.

theBIGone2087 · Answer

OK cool... does this need to be done in recovery/internet recovery?

theBIGone2087 · Answer

Looks like we are good to go, windows is installing as we speak with no issues so far. Thanks again for all the help!!!

Loner T · Answer

Excellent. Please remember to back up macOS, Windows and create a Windows System Restore point.