I’m not a fan of the new Disk Utility in El Capitan. I had a drive with 3 partitions and I needed to make it a single partition drive. Disk Utility would not allow me to delete one of the partitions no matter what I tried.
So I used the following Terminal command:
diskutil partitionDisk /dev/disk2 GPT JHFS+ New 0b
To break it down:
1. diskutil - is a command line tool used for formatting disks.
2. patitionDisk - is an option that can be used in diskutil.
3. /dev/disk2 - is the location of the disk that you want to format. You can use the diskutil “list” option to find this information.
4. GPT - is the GUID Partition Table.
5. JHFS+ - is the default filesystem type that OS X uses.
6. New - This is the name of the partition. You can name it whatever you like.
7. 0b - This tells the command to use all available free disk space.