1、查看磁盘

~ ❯❯❯ diskutil list
/dev/disk2 (external, physical):
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:     FDisk_partition_scheme                        *16.0 GB    disk2
1:                 DOS_FAT_32                         16.0 GB    disk2s1

2、umount掉U盘

~ ❯❯❯ sudo diskutil umount /dev/disk2

3、将镜像写入U盘

~ ❯❯❯ sudo dd if=/Users/CBC/Desktop/CentOS-6.6-x86_64-bin-DVD1.iso of=/dev/disk2 bs=1M
4418+0 records in
4418+0 records out
4632608768 bytes (4.6 GB) copied, 949.662 s, 4.9 MB/s

4、用iostat命令查看磁盘写入状态

 ~ ❯❯❯ iostat -w 2