Show progress while copying with dd

Let me show you a little trick with the pv tool.
What is pv ? Pv is tool which can monitor the progress of data through a pipe.

apt-get install pv

Here is a simple example

dd if=/dev/zero bs=1M count=512 | pv -s 512M | dd of=/tmp/512M
512+0 records in60.5MB/s] [==========================================================================>    ] 96% ETA 0:00:00
512+0 records out
536870912 bytes (537 MB) copied, 6.27769 s, 85.5 MB/s
 512MB 0:00:06 [81.6MB/s] [=============================================================================>] 100%            
1048576+0 records in
1048576+0 records out
536870912 bytes (537 MB) copied, 6.27816 s, 85.5 MB/s

If we make hard disk clonning, we can use

pv -tpreb /dev/sda | dd of=/dev/sdb