LVM Storage Remote Backup

lvm_snapshot_remote_backup.sh

#!/bin/bash

# =========================================================
#           LVM Snapshot Remote Backup
#               Ismet Handzic 2019
# =========================================================
#
# This script creates a LVM partition snapshot and sends
# it to a remote location via rsync
#
# IMPORTANT:
#       - The system parition must be in LVM formate
#	- You must have free unalocated space in your volume group
#           - To reduce the current logical volume (LV), you must unmount the disk
#               - Can be done via Live USB (create with Balena Etcher)
#               - More info: 
#		  - https://www.tecmint.com/extend-and-reduce-lvms-in-linux/
# 		  - https://www.digitalocean.com/community/tutorials/how-to-use-lvm-to-manage-storage-devices-on-ubuntu-18-04#removing-or-downsizing-lvm-components
#       - You must set up a SSH key with the remote location
#            - Create a public and private SSH Key:
#                 ssh-keygen (default location, no password)
#            - Distribute the public key to remote machine:
#                 ssh-copy-id <REMOTE USERNAME>@<REMOTE HOST ADDRESS/IP>
#
#
# NOTES: 
#       - The size of the snapshot is the size of the changes. 
#         So, lots of anticipated changes, more size. However,
#         add more than you anticipate.
#       - You can use this scrip with a cron job running it
#         at regular intervals
#       - Can use the folloiwng to troubleshoot:
#            - pvs - list physical volumes
#	     - vgs - list volume groups
#            - lvs - list logical volumes
# 	     - pvscan - details about physical volumes
#            - vgdisplay - details about volume groups
#            - lvdisplay - details about locial volumes
# =========================================================

echo "==============================================="
echo
echo $(date)
echo
echo "Starting System LVM Snapshot Backup ..."
echo


# =========================================================
# This stops the script immediately if an error occurs
set -e


# =========================================================
# Script Variables for conveneince
SNAPSHOT_NAME="system_backup_snapshot_$(date +%Y_%m)"
LVM_SNAPSHOT_SIZE="50G"
REMOTE_USER="YOUR REMOTE USERNAME"
REMOTE_IP="192.168.X.XX"
REMOTE_SSH_PRIVATE_KEY="/home/$REMOTE_USER/.ssh/id_rsa"
REMOTE_DIR="/home/$REMOTE_USER/Backup_Jenkins_Server/Snapshot"


echo "Script Settings:"
echo "    Snapshot image name:     $SNAPSHOT_NAME"
echo "    Remote user name:        $REMOTE_USER"
echo "    Remote IP address:       $REMOTE_IP"
echo "    SSH key location:        $REMOTE_SSH_PRIVATE_KEY"
echo "    Remote backup directory: $REMOTE_DIR"
echo 

# =========================================================
# Creat the snapshot logical volume
echo "$(date +%T) - Creating snapshot logical volume ..."
lvcreate --size $LVM_SNAPSHOT_SIZE --snapshot --name $SNAPSHOT_NAME /dev/ubuntu-vg/root


# =========================================================
# Make the directory in the /mnt/ folder if it doesnt already exist
echo "$(date +%T) - Creating mount directory in /mnt ..."
if [ ! -d $SNAPSHOT_NAME ]; then
	mkdir /mnt/$SNAPSHOT_NAME
fi


# =========================================================
# Mount the snapshot (read-only) 
echo "$(date +%T) - Mounting snapshot logical volume ..."
mount -o ro /dev/ubuntu-vg/$SNAPSHOT_NAME /mnt/$SNAPSHOT_NAME/


# =========================================================
# Check to see if remote backup directory exists
echo "$(date +%T) - Creating directory in remote/destination location ..."
if ssh -i $REMOTE_SSH_PRIVATE_KEY $REMOTE_USER@$REMOTE_IP "[ ! -d $REMOTE_DIR ]"; then
	# If it does not exist, create it
    	ssh -i $REMOTE_SSH_PRIVATE_KEY $REMOTE_USER@$REMOTE_IP "mkdir $REMOTE_DIR"	
fi


# =========================================================
# Send the snapshot to a remote location
# Options:
# -v    - verbose
# -r    - recursive into directories
# -a    - archive mode
# -z    - compress
# -h    - human readable
# -p	- perserver permission
# -e "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
echo "$(date +%T) - Transfering snapshot files to remote location ..."
echo
rsync -razh -e "ssh -i $REMOTE_SSH_PRIVATE_KEY" /mnt/$SNAPSHOT_NAME/ $REMOTE_USER@$REMOTE_IP:$REMOTE_DIR
echo
echo "$(date +%T) - Transfer complete"


# =========================================================
# Unmount the snapshot
echo "$(date +%T) - Unmounting snapshot logical volume ..."
umount --lazy /mnt/$SNAPSHOT_NAME


# =========================================================
# Remove the snapshot logical volume
echo "$(date +%T) - Removing snapshot logical volume ..."
lvremove -y ubuntu-vg/$SNAPSHOT_NAME


# =========================================================
# Remove the directory in /mnt/
echo "$(date +%T) - Removing mount directory in /mnt/ ..."
rm -r /mnt/$SNAPSHOT_NAME


echo
echo "LVM snapshot backup complete! :)"
echo
echo