How to back up my entire system?

FILES

Refer to this howto: http://ubuntuforums.org/showthread.php?t=35087

In simple terms, the backup command is:

sudo tar czf /backup.tar.gz \
    --exclude=/backup.tar.gz \
    --exclude=/dev \
    --exclude=/mnt \
    --exclude=/proc \
    --exclude=/sys \
    --exclude=/tmp \
    --exclude=/media \
    --exclude=/lost+found \
    /

Add more --exclude= parameters if you need to.

It will create an archive of all your files at /backup.tar.gz, which should be copied to another computer or drive.

To restore your files when the system goes pear-shaped, use a Live CD. Mount the bad system under /media or /mnt and then run tar xf /path/to/drive/with/backup.tar.gz -C /mnt (or /media).

GRUB

This will not cover GRUB, however you can easily reinstall it by following this guide here. You only need to do steps Three and Four.

Noone noticed clonezilla. It makes a complete image of your hard drive, so it backups absolutely everything. It's as easy as burning an iso or creating a bootable flash drive.

The actual backup takes a while, but is the most reliable.

To clone your system to another system. Or make a backup. In terminal type:

dpkg --get-selections | grep -v deinstall > ubuntu-files

This command makes a file list of all installed packages in your system (and stores it in present working directory). Backup this file in hdd, email, etc...(this file is very small).

In the freshly installed ubuntu system run:

sudo dpkg --set-selections <./ubuntu-files (will set it up and)

apt-get -y update
apt-get dselect-upgrade

This will install only those packages you had installed (with apt-get) in the old system.

                                    (OR)

You could back up all the .deb packages from /var/cache/apt/archives/ and install them manually using:

dpkg -i *.deb

And after that running an update cycle later.

Here is a solution I use with SquashFS. It is quite similar to TAR.GZ solution proposed earlier, but has some major benefits.

SquashFS is a compressed file system, which is completely stored in one file. This file can be mounted to an existing system and accessed in a usual way, like any other partition. The difference to TAR.GZ is that SquashFS is a full-blown file system with random access to files, while TAR is just one big concatenated file.

This means that if you want to mount some large backup of your whole file system, for TAR.GZ it would take like 5 hours (in my experience) and for SquashFS it would take just minutes/seconds. The same is true also for the compression/backup operation, SquashFS is many times faster.

UPDATE 2017-01-31: It appears that not only can you mount squashfs file, but also open it as a usual archive with familiar apps like File Roller on Linux and 7-Zip on Windows, etc.

So here is a command I use to back up my root folder:

sudo mksquashfs / /path/to/backup/hdd/root-backup.sqsh -e home media dev run mnt proc sys tmp

where "-e" switch excludes folders you want to exclude (like virtual and external Linux folders in my example).

After the backup is done, I can now mount it:

sudo mkdir /mnt/root_backup
sudo mount /path/to/backup/hdd/root-backup.sqsh /mnt/root_backup -t squashfs -o loop

Now just wait couple minutes (depending on size of the archive) and enjoy all your files at /mnt/root_backup folder.

Same can be done for /home/myname folder, e.g.

sudo mksquashfs /home/myname /path/to/backup/hdd/home-backup.sqsh -e Dropbox GoogleDrive

I exclude Dropbox and GoogleDrive here to avoid any potential problems in the future, in case I restore those folders from backup and they become messing with the actual files in the cloud.

Check more info at http://tldp.org/HOWTO/SquashFS-HOWTO/creatingandusing.html

We can also do backup of system with rsync & exclude files & folders that we don't want. Here is the following command to do this :

#rsync -aAXv --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} /* /path/to/backup/folder

Using the -aAX set of options, the files are transferred in archive mode, ensuring that symbolic links, devices, permissions and ownerships, modification times, ACLs and extended attributes are preserved

The --exclude option will cause files that match the given patterns to be excluded.

REFERENCE : Full system backup with rsync

You can use Remastersys to create a bootable live CD/DVD image. This will install like a normal Ubuntu CD.

To install Remastersys, you first need to add a repository:

deb http://www.geekconnection.org/remastersys/repository karmic/

You can then install it from the Software Centre as usual.

Once installed, use it to make a 'dist' backup. This means that user data will be excluded from the ISO image.

This is often used to create custom distributions but is still useful for the backup task you have in mind. One caveat is that it may fail if the contents of / (minus user data in /home) takes up too much memory because the ISO file format can only hold ~4GB data. Remastersys uses a file system called squashfs to compress your data so you should be OK with up to ~8GB.

Try Remastersys.
With that program you can do liveCD (just the same as Ubuntu installation iso file) of your system with ability to install it on hard drive. Works pretty simple (if you know how to burn iso to USB/CD/DVD).
Works perfectly on my 11.10 and 11.04, and older ones as well.

Installation:
edit file /etc/apt/sources.list
add: # Remastersys
deb http://www.geekconnection.org/remastersys/repository karmic/ and save
Then run in terminal:
sudo apt-get update
sudo apt-get install remastersys

I turned afrish's excellent answer into a script for myself. Thought it could be useful for those wishing to automate it. The nice thing is that since the script can live on the NAS it will only execute if it's connected.

The script (can be copied to any location - preferably the NAS itself) and will build the backups in the same folder.

Backups Script

make_backups_root_and_home.sh

#!/usr/bin/env bash

set -e

if [ "$EUID" -ne 0 ]
  then echo "Please run as root"
  exit
fi

log="log.txt"
power=$(cat /sys/class/power_supply/AC/online)
start_date=$(date +%Y%m%d_%H%M%S)

if (( $power == 1 )); then
    echo "Starting backup $log at $start_date" >> $log

    # ROOT IMAGE
    root_backup_file=$start_date-root-backup.sqsh
    sudo mksquashfs / $root_backup_file -e home media dev run mnt proc sys tmp nfs

    # ALL HOMES IMAGE
    home_backup_file=$start_date-home-backup.sqsh
    sudo mksquashfs /home $home_backup_file -e Dropbox GoogleDrive

    finish_date=$(date +%Y%m%d_%H%M%S)
    echo "Completed $root_backup_file and $home_backup_file at $finish_date" >> $log
else
    echo "Power is not plugged in... skipped on $start_date" >> $log
fi

Don't forget to chmod +x make_backups_root_and_home.sh!

Linux Cronjob

To enable the cronjob:

sudo su
crontab -e

For Sunday at 1am, append:

00 01 * * sun  /nas_path/to/your/make_backups_root_and_home.sh >> /nas_path/to/your/log.txt 2>&1

Testing Backups!

As with all good backups, they should be tested! Finally, we can create a script to mount the last available backup (since they are ordered by date).

mount_last_backup.sh

#!/usr/bin/env bash

sudo mkdir -p /mnt/root_backup
sudo mkdir -p /mnt/root_home

#UMOUNT ANY
sudo umount /mnt/root_backup
sudo umount /mnt/home_backup

last_root=$(ls -Xrt -1 *root-backup* | head -n 1)
last_home=$(ls -Xrt -1 *home-backup* | head -n 1)

sudo mount $last_root /mnt/root_backup -t squashfs -o loop
sudo mount $last_home /mnt/home_backup -t squashfs -o loop

TimeShift.

TimeShift protects your system by taking incremental snapshots of the file system at regular intervals. These snapshots can be restored later to bring your system to the exact state it was in at the time when the snapshot was taken.

Open the terminal and run the following command

sudo apt-add-repository -y ppa:teejee2008/ppa
sudo apt-get update
sudo apt-get install timeshift

Screenshots

Here is a good tutorial using PartImage.