Findings

Frankly speaking, this is just another file.

Post attaching a volume to an EC2 instance (NetBSD in this case), remote backup using dd is done like this:
			> tar zcf - . | ssh -i key-file.pem username@publi-ip-here "dd of=/dev/xbd3"
			[ . is $PWD and xbd3 is the location where the new raw-block device is attached (captured from grep | tail | some-regex-here) ]
			[ grep | tail | some-regex-here seems to be right because the latest attached volume will be the bottom-most with respect to
			  other entries of the same type which are already present there, maybe at some position above that in dmesg ]

I have tested the backup and it worked well output is as follows:
$ tar cvzf - aws | ssh name@ip "dd of=/home/backup/backup.tar.gz"
aws/
aws/ec2-backup
aws/ec2-backup_1
aws/ec2-backup_full
...........
..........
aws/rkc.pem
aws/rootkey.csv
aws/test/
2986034+1 records in
2986034+1 records out
1528849884 bytes (1.5 GB) copied, 460.558 s, 3.3 MB/s

Whatever was done in Hw2 and 4 helped alot to get to a understanding level of this code.
As we are repeating many steps in each case we can make use of functions, hence made functions.
We have to find the volume which will be attached in that case we can take the lsblk output grep and obtain the greatest value of min.
Experiment what i have done is created an Linux instance and created two volumes and attached it and this is the output 1,2 and 3 time 
sblk
NAME  MAJ:MIN RM SIZE RO MOUNTPOINT
xvda1 202:1    0   8G  0 /

lsblk
NAME  MAJ:MIN RM SIZE RO MOUNTPOINT
xvda1 202:1    0   8G  0 /
xvda2 202:2    0   1G  0

 lsblk
NAME  MAJ:MIN RM SIZE RO MOUNTPOINT
xvda1 202:1    0   8G  0 /
xvda2 202:2    0   1G  0
xvda3 202:3    0   1G  0
This will not work for every OS that was the take when i was discussing with my Team mates about it.