How to mount another EBS as /var on EC2 (ubuntu)

mount_ebs.sh

#!/bin/bash
#attach the EBS to /dev/sdf before running it

# format EBS
sudo mkfs -t ext4 /dev/xvdf

# copy original /var to /dev/xvdf
sudo mkdir /mnt/new
sudo mount /dev/xvdf /mnt/new
cd /var
sudo cp -ax * /mnt/new
cd /
sudo mv var var.old

# mount EBS as new /var
sudo umount /dev/xvdf
sudo mkdir /var
sudo mount /dev/xvdf /var

# update fstab file to mount EBS on system startup
sudo cp /etc/fstab fstab
sudo chmod 666 fstab
echo "/dev/xvdf /var ext4 defaults,noatime 1 1" >> fstab
sudo chmod 644 fstab
sudo mv /etc/fstab /etc/fstab.old
sudo mv fstab /etc/fstab