MacOS – Inconsistent disk capacity reports in OS X – I’m missing 365GB of the 2 TB

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Coincidentally I have noticed that the disk capacity reports in "About this Mac" and the Terminal when running diskutil list both report inconsistent capacities for an external hard disk drive.

This is an 2TB external hard drive. However, when adding the capacities of all partitions I get a value which is significantly below:

0.2+885.2+0.1+400.0+0.1+300.0+0.1+49.5=1635.2 (GB)

How is this possible? Where did the remaining ~365GB go?

This disk had been formatted and used under OSX Mountain Lion.

/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *2.0 TB     disk2
   1:                        EFI                         209.7 MB   disk2s1
   2:          Apple_CoreStorage                         885.2 GB   disk2s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk2s3
   4:          Apple_CoreStorage                         400.0 GB   disk2s4
   5:                 Apple_Boot Boot OS X               134.2 MB   disk2s5
   6:          Apple_CoreStorage                         300.0 GB   disk2s6
   7:                 Apple_Boot Boot OS X               134.2 MB   disk2s7
   8:       Microsoft Basic Data EXCHANGE                49.5 GB    disk2s8
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Time Machine           *299.7 GB   disk3
/dev/disk4
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Media                  *884.8 GB   disk4
/dev/disk5
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Time Machine 2         *399.7 GB   disk5

Best Answer

Unformatted space.

eg, I have a 500Gb disk with just a 27Gb partition:

   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *500.1 GB   disk0
   1:                       0xBF                         26.8 GB    disk0s1

You can confirm this in Disk Utility or a tool like iPartition.

In Disk Utility click on the drive itself, not a partition of it. Then, under the partitions tab you should see each partition, and then the greyed out freespace available on the drive. You can select it and it'll show you how much you have.

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