Clone disk using DD Over Netcat or SSH

dd bs=16M if=/dev/sda | ssh root@serverB "dd bs=16M of=/dev/sda"

dd bs=16M if=/dev/sda3 | ssh root@serverB "dd bs=16M of=/dev/sda3"

Clone disk partition using dd over SSH

## Destination server B nc -l -p 19000 | bzip2 -d | dd bs=16M of=/dev/sda ## Source server A dd bs=16M if=/dev/sda status=progress | bzip2 -c | nc root@serverB 19000 ## Then , use tcpdump to check traffic in serverB tcpdump port 1900 ## Finally, You'll get a DD output on both ends summarizing the read/write time and bytes transferred when the process is complete.

Clone disk partition using dd over Netcat (no encryption stream) with bzip compression

### Average of Methods
## Each transfer method was repeated three times with the same empty 10GB partition and then averaged here. 
## The tests were conducted within our datacenter, from two servers within the same facility, in different VLANs, each uplinked at 100Mbit:

Time Elapsed (Sec)	Speed (MB/s)
Over SSH	1787.4	6.1
Over Netcat (no compression)	1622.4	6.6
Over Netcat (bzip compression)	889.3	12.1
Over Netcat (16M block size + bzip)	490.0	21.9

Average Time Savings
Time Savings (Seconds)	Percentage Savings
Over SSH	-	0%
vs Netcat (no compression)	165.0	9%
vs Netcat (bzip compression)	898.1	50%
vs Netcat (16M block size + bzip)	1297.3	73%


Original Reference :
https://www.ndchost.com/wiki/server-administration/netcat-over-ssh