#!/bin/sh
# copies whole harddisks with mbr and everything.
# arguments: input-device output-device
# example: clone-disk /dev/sda /dev/sdc
# dependencies: dd
# dd options used:
#   "bs=" sets the block size. defaults to 512 bytes, which is the "classic" block size for hard drives since the early 1980s,
      but is not the most convenient
#   "noerror" instructs dd to continue operation, ignoring all read errors. default behavior for dd is to halt at any error
#   "sync" fills input blocks with zeroes if there were any read errors, so data offsets stay in sync
#   "status=progress" shows periodic transfer statistics which can be used to estimate when the operation may be complete

dd if="$1" of="$2" bs=64K conv=noerror,sync status=progress