How to modify partition size within OS X 10.10 System or delete partition how to modify partition size or delete partition in OS X 10.10 system

When OS X 10.10 is upgraded, the partition of the hard disk becomes a logical partition (Logical Volume Group). This way you cannot partition the disk using disk tools, including resizing, deleting and adding partitions, and so on. If you need to modify or delete a partition within an OS X 10.10 system, you need to convert the logical partition first.

Here's how it works:

1. Restart your computer and press Command-r to enter the system recovery partition.

Select Chinese language to enter.

2. Click the Go to Disk tool

3. When you find that you cannot modify the partition size or delete the partition. You will find that your hard drive type is: Logical file set Logical Volume Group

4. To make sure that the operation is correct, first fix the disk, and then repair the disk file permissions. After exiting the Disk utility, select Tools on the menu bar-open terminal.

5. Enter the instruction Diskutil corestorage list to make a listing of the existing disk partitions. The ID used to view the disk.

6, enter the Diskutil corestorage revert partition ID to convert the logical partition to a normal partition.

7. You can change the size of the disk after the conversion.

Special reminder: The operation is risky, please remember to back up the file!