Linux Backup #

Clonezilla Backups #

You can use clonezilla to make full backups of your complete drive or the Raspberry SD card https://clonezilla.org/

Kopia Backups #

To backup all kind of data I use Kopia
- It supports incremental backups, which allow to restore to different points in time
Install Kopia
Guide on how to use Kopia
There are basically two backup mechanisms: push and pull
- With push, the client containing the data is pushing the data to a backup server
- With pull, the backup server is asking a client to get its data to backup it
Kopia only supports the push mode (so the client side mode)
On our client, containing the data, we initialize a repository, which will be located on our backup driver or also backup server
For a backup drive simply create a repo via
- kopia repository create filesystem --path /path/to/backup/drive/folder
We create and connect to a backup server repository e.g. via ssh (sftp)
- We already have to have a working ssh connection from our client to our server with ssh keys set up
- kopia repository create sftp --path=/home/freddy/Backup/pi4 --host=freddy-desktop.lan --username=freddy --keyfile=/root/.ssh/id_rsa --known-hosts=/root/.ssh/known_hosts
That is all, now we are connected via Kopia to this backup repository
- Kopia will always reconnect to this reposiotory, except if you manually disconnect at some point via kopia repository disconnect
- Then you can reconnect via kopia repository connect filesystem --path /path/to/backup/drive/folder
  - or via kopia repository connect sftp --path=/home/freddy/Backup/pi4 --host=freddy-desktop.lan --username=freddy --keyfile=/root/.ssh/id_rsa --known-hosts=/root/.ssh/known_hosts

Snapshot #

Now we can create backups (snapshots) of various data located on our client
Examples
- kopia snapshot create /opt/docker
- or if you want to first dump a database from a docker container, to be sure that it is in a valid state when restoring do e.g.:
  - docker exec postgres-synapse pg_dumpall -U synapse > /databases/docker-synapse-postgres.dump && kopia snapshot create /databases/docker-synapse-postgres.dump && rm /databases/docker-synapse-postgres.dump
- kopia snapshot create /mnt/data/nextcloud

Ignore #

You can also ignore specific directories during the backup process
- Example: sudo kopia policy set --add-ignore '*' /home/frederik/Nextcloud /home/frederik/sciebo/

Sync Backup to another Backup Repository #

If we want to sync our backup from one backup repository to another this is also possible with kopia
- Forum question about this
Connect to the source repository if not already connected
- kopia repository connect filesystem --path=/home/freddy/Backup/pi4
Now you can sync the repo to the target repository (must be empty folder or have the same kopia.repository file) and specify it via path
- kopia repository sync-to filesystem --path /media/freddy/Backup_Freddy/backup-server
- Here you can also use sftp instead of the filesystem again

Mount / Restore Backup #

You can mount the backup to check the files
kopia mount snapshot-id ~/my-mount-location
kopia restore snapshot-id ~/my-mount-location

My Server Backups #

On my main server, I have an additional backup drive
My main server and my other Raspberry Pi both connect to this same backup drive via kopia and do regular backups via cron every 1h
Since it is risky to only have one backup repository, I also sync the repository to my PC ones per Day via ssh, such that the complete repository is also available at a drive of my PC
And again I have another external drive, which I sometimes attach to my PC to also sync the repository on my PC to the external drive, to have another 3rd backup location
The backup scripts are also available in my repos
- Server scripts
- Scripts on my PC

My Home Backups #

Use Kopia
- sudo kopia repository create filesystem --path /media/frederik/Backup-i11/backup-i11
Frequency
- sudo kopia policy set --global --keep-annual 1 --keep-monthly 3
Ignore folders
- sudo kopia policy set --add-ignore '*' /home/frederik/Nextcloud /home/frederik/sciebo/
- sudo kopia policy set --global --add-ignore '.cache' --add-ignore 'cache'
Test it
- sudo kopia snapshot estimate /home/frederik
Use a launcher to launch it easily or automate the process with a script
I, personally, have a script run by anacron once a day, which automatically checks the network interface, if that is the home network, it connects to a backup server and triggers a backup of the home directory. Additionally, it backs up a list of all installed programs. A notification is sent to the desktop, if the backup is done or if it fails, with a link to the log file. See here for the script

Backup to smb drive:

mount to local filesystem
also add “nofail” if drive not always available
then do normal kopia backup to filesystem

Android Backups #

We want to back up everything under

/sdcard - normal user data
/data/data - internal private app data, not visible to normal user

Backup #

Prepare ssh acces on android phone Other OS#SSH Server on android

So we will prepare a script for the backup server and then we will prepare android to start this script

On backup server site:

Create kopia backup repository
mount android via sshfs sshfs root@192.168.0.23:/data/data/ /mnt/android/data-data -p 2222
- sshfs root@192.168.0.23:/sdcard/ /mnt/android/sdcard -p 2222
And now you can create snapshots
- kopia snapshot create /mnt/android/data-data/
- kopia snapshot create /mnt/android/sdcard/
And now umount again
- umount /mnt/android/data-data
- umount /mnt/android/sdcard
This can be put into a script, which automates this process

On Android site:

We want to automate the backup, by calling the script on the server side by using the tasker app
You can use tasker to create a new task
- first launch app action to start the simplessh app
- then a run shell action to ssh into the server and start the backup script
  - /data/data/com.termux/files/usr/bin/ssh root@192.168.0.100 /root/scripts/backup-android.sh
- now you can kill the sshd app
- And send a notification that the backup is done
  - Optionally with the result of the script, which can be saved in a file and also stored in a tasker variable to be displayed via the notification

Example tasker process:

Task: Backup-android
    
    A1: Launch App [
         Package/App Name: SimpleSSHD ]
    
    A2: Run Shell [
         Command: {
         /data/data/com.termux/files/usr/bin/ssh root@192.168.0.100 /root/scripts/my-backup-android.sh
         } >  /sdcard/.tmp-backup-android.log 2>&1
         Timeout (Seconds): 0
         Use Root: On
         Use Global Namespace: On
         Continue Task After Error:On ]
    
    A3: Kill App [
         App: SimpleSSHD
         Use Root: On ]
    
    A4: Run Shell [
         Command: /data/data/com.termux/files/usr/bin/tail -n 5 /sdcard/.tmp-backup-android.log
         Timeout (Seconds): 0
         Use Root: On
         Store Output In: %res
         Use Global Namespace: On ]
    
    A5: Notify [
         Title: Backup Done
         Text: %res
         Icon: hd_device_access_storage
         Number: 0
         Priority: 3
         LED Colour: Green
         LED Rate: 0
         Category: Backup ]

Restore #

If restoring make sure, that the correct owners are set for the /data/data/ folders for each app

every installed app has its own linux user and this must fit to the restored data folder
- If reinstalling apps, this user changes
- So reinstall an app and check the user ID: ls -la /data/data/com.your-app
- And after restoring with kopia, for example via:
  - sshfs root@192.168.0.23:/data/data/ /mnt/android/data-data -p 2222
  - mkdir -p /mnt/some-tmp-location
  - kopia snapshot restore /mnt/android/data-data/us.zoom.videomeetings --snapshot-time=latest /mnt/some-tmp-location
  - chown -R 10335:10335 /mnt/some-tmp-location
  - chown -R 10335:20335 data/data/us.zoom.videomeetings/code_cache/ - necessary since cache has a different group
  - And now restoring
  - rsync -av ./mnt/some-tmp-location/us.zoom.videomeetings/ /mnt/android/data-data/us.zoom.videomeetings/ --delete
Restore other external data from sdcard, the same way
You can use the script I provided in my scrips repo for automation
Also create a tasker task analog to the backup task
- Just specifc a tasker variable in additon, which specifys the app name, that should be restored

Borg Backups #

Borg is similar to Kopia and is being used by the nextcloud-aio container to do automatic backups. Here are some hints on how to restore backups manually if need be. Normally, one would use the built-in restore tool from nextcloud-aio, though.

Get info of borg repo
- sudo borg info /mnt/backup/backup-nextcloud-aio/borg
- sudo borg list /mnt/backup/backup-nextcloud-aio/borg
To restore from borg backup files to current directory (remove –dry-run) sudo borg extract --list --dry-run /mnt/backup/backup-nextcloud-aio/borg::20230219_030107-nextcloud-aio nextcloud_aio_volumes/nextcloud_aio_nextcloud_data/Freddy/files/some-file

Unison Backups #

I recently switched to use Kopia for backups, so I would recommend kopia instead

Use unison as file sync program unison Manual for unison

Install it via:

sudo apt install unison

But same version on host and client needed, so maybe install .deb manually and download somewhere if both Linux versions do not have the same version https://pkgs.org/download/unison

A unison config for a nextcloud backup:

# Unison preferences
label = Nextcloud Backup
root = ssh://root@pi4.lan//mnt/data/nextcloud
force = ssh://root@pi4.lan//mnt/data/nextcloud
root = /home/freddy/Backup/nextcloudbackup/data
batch = true
group = false
owner = false
perms = -1
times = true
links = true
retry = 1
logfile = /home/freddy/Computer/Pi_Backup_Log/nextcloud_unison.log

And file for backups to an external drive

# Unison preferences
label = External Backup
root = /home/freddy/Backup
force = /home/freddy/Backup
root = /media/freddy/Backup_Freddy/pi_Backups
ignore = Path lost+found
ignore = Path .Trash-1000
auto = true
group = false
owner = false
perms = -1
times = true
links = true
retry = 1
log = false

You can execute unison backup manually via:

unison my-profile-name