dd指令:convert and copy a file
用法:
dd if=/path/from/src of=/path/to/dest
bs=#:block size, 複制單元大小;
count=#:複制多少個bs;
磁盤拷貝:
dd if=/dev/sda of=/dev/sdb
備份mbr
dd if=/dev/sda of=/tmp/mbr.bak bs=512 count=1
破壞mbr中的bootloader:
dd if=/dev/zero of=/dev/sda bs=256 count=1