1. ☁  Desktop [master] ⚡ hdiutil convert -format UDRW -o ./ubuntu-18.04-desktop-amd64 ./ubuntu-18.04-desktop-amd64.iso    # 将ISO转为DMG
    2. 正在读取Driver Descriptor Map（DDM：0）…
    3. 正在读取Ubuntu 18.04 LTS amd64          （Apple_ISO：1）…
    4. 正在读取Apple（Apple_partition_map：2）…
    5. 正在读取Ubuntu 18.04 LTS amd64          （Apple_ISO：3）…
    6. .............................................................................
    7. 正在读取EFI（Apple_HFS：4）…
    8. .............................................................................
    9. 正在读取Ubuntu 18.04 LTS amd64          （Apple_ISO：5）…
    10. ..............................................................................
    11. 已耗时： 2.082s
    12. 速度：880.0M 字节/秒
    13. 节省：0.0%
    14. created: /Users/huqilin/Desktop/ubuntu-18.04-desktop-amd64.dmg
    15. ☁  Desktop [master] ⚡ diskutil list    # 得到 U 盘设备号
    16. /dev/disk0 (internal):
    17.    #:                       TYPE NAME                    SIZE       IDENTIFIER
    18.    0:      GUID_partition_scheme                         251.0 GB   disk0
    19.    1:                        EFI EFI                     314.6 MB   disk0s1
    20.    2:                 Apple_APFS Container disk1         250.7 GB   disk0s2
    21. /dev/disk1 (synthesized):
    22.    #:                       TYPE NAME                    SIZE       IDENTIFIER
    23.    0:      APFS Container Scheme -                      +250.7 GB   disk1
    24.                                  Physical Store disk0s2
    25.    1:                APFS Volume Macintosh HD            112.5 GB   disk1s1
    26.    2:                APFS Volume Preboot                 21.1 MB    disk1s2
    27.    3:                APFS Volume Recovery                517.8 MB   disk1s3
    28.    4:                APFS Volume VM                      3.2 GB     disk1s4
    29. /dev/disk2 (external, physical):
    30.    #:                       TYPE NAME                    SIZE       IDENTIFIER
    31.    0:     FDisk_partition_scheme                        *7.8 GB     disk2
    32.    1:                  Apple_HFS USB8G                   7.8 GB     disk2s1
    33. ☁  Desktop [master] ⚡ diskutil unmountDisk /dev/disk2    # 卸载 U 盘设备
    34. Unmount of all volumes on disk2 was successful
    35. ☁  Desktop [master] ⚡ sudo dd if=ubuntu-18.04-desktop-amd64.dmg of=/dev/disk2 bs=1m    # 创建可启动的 USB 驱动盘
    36. Password:
    37. 1832+1 records in
    38. 1832+1 records out
    39. 1921843200 bytes transferred in 207.200284 secs (9275292 bytes/sec)
    40. ☁  Desktop [master] ⚡ diskutil eject /dev/disk2    # 弹出磁盘
    41. Disk /dev/disk2 ejected