How to make the Linux bootable USB on OSX

download ISO iamge from web.

• Visit Centos’ web page CentOS
• Download the iso image you’d like to boot.

Convert from ISO to img

• Wten the Iamge file has completed download.
• Open up terminal
• command "hditutil" to convert the .iso to an .img file

  $hdiutil convert -format UDRW -o target.img CentOS-7.0-1406-x86_64-Everything.iso
  Master Boot Record(MBR : 0) ...
  CentOS 7 x86_64                 (Apple_ISO : 1) ...
  (Type EF : 2) ...
  CentOS 7 x86_64                 (Apple_ISO : 3) ...
  ...............................................................................
  Elapsed Time: 56.861s
  Speed: 118.4M바이트/초
  Savings: 0.0%
  created: /tmp/target.img.dmg
  

copy USB bootable device

• Use the ‘dd’ utility to copy your USB device

$ diskutil list
/dev/disk0
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:      GUID_partition_scheme                        *121.3 GB   disk0
1:                        EFI EFI                     209.7 MB   disk0s1
2:                  Apple_HFS Leo                     120.5 GB   disk0s2
3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk3
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:     FDisk_partition_scheme                        *8.1 GB     disk3
1:             Windows_FAT_32                         8.1 GB     disk3s1

$ diskutil unmountDisk /dev/disk3
Unmount of all volumes on disk3 was successful

$ time sudo dd if=target.img.dmg of=/dev/disk1 bs=1m
Password:
6734+1 records in
6734+1 records out
7061702656 bytes transferred in 2632.351800 secs (2682659 bytes/sec)

43m55.224s
0m0.034s
1m21.995s

complete a makes USB bootable device

• You may be done!
• Boot from the USB on your target machine.