Remove partition failed - the partition is gone, but now there is missing space. How do I get it back? I was trying to get rid of an old Bootcamp partition I didn't want anymore. I followed these instructions to remove a partition using Disk Utility, but the removal failed. Now the partition is gone, but the space it used to occupy hasn't been merged back to the main disk partition - it's just gone. My SSD is 1 TB, but Macintosh HD is only 775 GB, the same as it used to be.

What happened to this extra space and how can I get it back? And why did it leave me in this weird half-removed position instead of removing the partition properly?

Here's what my Disk Utility looks like now:



Here's what comes up when I enter "diskutil list":

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       
IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage Macintosh HD            774.7 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1 (internal, virtual):
   #:                       TYPE NAME                    SIZE       
IDENTIFIER
   0:                  Apple_HFS Macintosh HD           +774.3 GB   disk1
                                 Logical Volume on disk0s2
                                 8679E121-03C8-47B0-844E-961A437E5CA5
                                 Unencrypted
Backup your main volume.
Open Terminal.app
Check the file system integrity of your main partition: diskutil verifyVolume disk0s2
If everything is fine, expand your logical volume group (and the inherent logical volume):

diskutil cs resizeStack lvUUID size


In your case that's:

diskutil cs resizeStack 8679E121-03C8-47B0-844E-961A437E5CA5 0g


If you run Sierra the magic size 0g may fail and you have to enter a distinctive size:

diskutil cs resizeStack 8679E121-03C8-47B0-844E-961A437E5CA5 999300m


If you get an error like: Error: -69771: The target disk is too small for this operation choose a slightly smaller size like 999200m until you are successful.
If you get a different type of error, the whole (previous) Disk Utility operation failed and corrupted the internal structure of the LVG. You have to restore the main volume from your Time Machine backup then.