使用命令行操作，非常easy，可是操作不当非常危急！
免责声明：假设操作不当造成的数据丢失，本人概不负责。
为什么？
不是有OSX恢复磁盘助理嘛？是的。假设仅仅想使用GUI的软件。能够去苹果官方站点：http://support.apple.com/kb/DL1433?viewlocale=zh_CN
唯一的原因就是：生命不息，折腾不止；只是还有另外一个诱因，就是看看究竟官方的恢复磁盘助理的原理，换句话说，用自己的办法达到相同的效果。
前提：你有一个工作的Recovery HD，你的Mac支持U盘启动。
1. 准备一个空白的不小于1GB的U盘。事实上650MB的就能够。
2. 执行命令，并记住各个參数：
diskutil list
我的机器是：
$ diskutil list /dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *160.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 159.7 GB disk0s2
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 GB disk1
1: Apple_HFS A 346.9 MB disk1s1
2: Apple_Boot Recovery HD 693.8 MB disk1s2
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_HFS OSX94 29.5 GB disk2s2
3: Apple_Boot Recovery HD 650.0 MB disk2s3
4: Apple_HFS Data 58.0 GB disk2s4
5: Apple_HFS OSX10DP 23.5 GB disk2s5
6: Apple_Boot Recovery HD 650.0 MB disk2s6
7: Apple_HFS _OSX10DPInstaller_ 7.3 GB disk2s7
我要操作的是disk1这个盘。源Recovery HD是disk2s6。它是OS X 10.10 DP3的恢复盘。
3. 创建U盘恢复分区
执行命令和显示：
$ sudo -s
$ diskutil partitionDisk disk1 1 GPT jhfs+ Recovery\ HD 100% Started partitioning on disk1
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Formatting disk1s1 as Mac OS Extended (Journaled) with name Recovery HD
Initialized /dev/rdisk1s1 as a 992 MB case-insensitive HFS Plus volume with a 8192k journal
Mounting disk
Finished partitioning on disk1
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 GB disk1
1: Apple_HFS Recovery HD 1.0 GB disk1s1
4. 制作：
$ diskutil unmountDisk disk1 Unmount of all volumes on disk1 was successful $ gpt remove -b 40 disk1
disk1s1 removed $ gpt add -b 40 -t 426F6F74-0000-11AA-AA11-00306543ECAC disk1
disk1s1 added $ gpt -r show disk1
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 2032634 1 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
2032674 32 Sec GPT table
2032706 1 Sec GPT header $ dd if=/dev/dsik1s6 of=/dev/disk1s1 $ diskutil mount disk1s1
$ bless --folder /Volumes/Recovery HD/com.apple.recovery.boot
5. 验证：
$ diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *160.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 159.7 GB disk0s2
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 GB disk1
1: Apple_Boot Recovery HD 1.0 GB disk1s1
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk2
1: EFI EFI 209.7 MB disk2s1
2: Apple_HFS OSX94 29.5 GB disk2s2
3: Apple_Boot Recovery HD 650.0 MB disk2s3
4: Apple_HFS Data 58.0 GB disk2s4
5: Apple_HFS OSX10DP 23.5 GB disk2s5
6: Apple_Boot Recovery HD 650.0 MB disk2s6
7: Apple_HFS _OSX10DPInstaller_ 7.3 GB disk2s7
6. 測试：
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