org-roam/20230607105613-borg_backup.org

borg-backup

• Install borg on all machines that store data (client1, client2 etc.) and on which data is to be stored (backup-server)
  • command
• Borg installed
  • clients
    • W0
    • W10
  • backup-server
    • W11
• Create ssh-key and .ssh directory
  • command
• Change the file on backup-server, which before created in /home/<user>/.ssh/authorized_keys and write following command before the corresponding ssh-key
• Create on client a backup directory and a backup.sh file
• Create on backup-server a backup directonary and for each client a folder inside the backup folder
• Create a borg repo for created client folder
• Create a backup
  • List & mount a backup for each client
• Restore backup
• Create a crontab as user
• Create a prune-backup.sh file for to automatically manage the created backups.

Borg (previously called Attic) is deduplicating backup software for various Unix-like operating systems.

Install borg on all machines that store data (client1, client2 etc.) and on which data is to be stored (backup-server)

command

  yay borg

Borg installed

clients

W0

W10

backup-server

W11

Create ssh-key and .ssh directory

command

  mkdir -p ~/.ssh
  ssh-keygen

Note: Press 1x enter for save the file in /home/<user>/.ssh/id_rsa, following enter two times the passphrase, which is created before in keepassxc.

  cat .ssh/id_rsa.pub
  cat .ssh/id_rsa.pub | ssh <user>@<client> "cat >> .ssh/authorized_keys"

Note: Do this for all clients which want to save data. Note: Check on backup-server with cat ~/home/<user>/.ssh/authorized_keys whether the keys have been piped over.

Change the file on backup-server, which before created in /home/<user>/.ssh/authorized_keys and write following command before the corresponding ssh-key

command="borg serve --restrict-to-path /home/<user>/backups/<client> --append-only"

Create on client a backup directory and a backup.sh file

  mkdir -p backups
  touch backup.sh
  sudo nano backup.sh

For the last command you need root priviliges or sudo. Insert following script into the backup.sh file

#!/bin/bash
DATE=`date +"%Y-%m-%d"`
REPOSITORY="ssh://<user>@<ip-adress>:22/~/backups/<client>"
export BORG_PASSPHRASE="<which is created before> " 
borg create $REPOSITORY::$DATE /home/<user>/<path_which_want_to_be_saved> --exclude-caches

Make script executable

  chmod +x ./backup.sh

Create on backup-server a backup directonary and for each client a folder inside the backup folder

  mkdir -p backups/<for_each_client>

Note: The name <for_each_client> folder must be the same like the command in the /home/<user>/.ssh/authorized_keys file on the backup-server, which is written before the corresponding ssh-key

Create a borg repo for created client folder

  borg init --encryption=repokey backups/<for_each_client>

After enter two times the passphrase for each client. Choose yes/no if the passphrase should be displayed.

Create a backup

The following command is listed in path /home/<user>/backups on each client

  ./backup.sh

Answer "yes" to fingerprint. Note: If the backup failed, change the owner/user for the folder, which want to be saved.

  chmod -r <folder_which_need_permission>

List & mount a backup for each client

  borg list /home/<user>/backups/<client>
  mkdir  mnt
  borg mount /home/<user>/backups/<client> mnt/

Enter the passphrase.

Restore backup

To restore the backup the borg key and the corresponding passphrase is neccessary. Get the borg key on the backup-server from each client

  borg key export /home/<user>/backups/<client> key-export_<client>
  cat key-export_<client>
  rm key-export_<client> (after copy and saved on a extern hdd)

Create a crontab as user

  crontab -e
  0 2 * * * /home/<user>/backups/backup.sh

Create a prune-backup.sh file for to automatically manage the created backups.

  #!/bin/bash

  # <client>:
  export BORG_PASSPHRASE="<which_is_created_before>"
  borg prune -v ~/backups/<client> \
       --keep-daily=30
       --keep-weekly=5
       --keep-monthly=12

Make script executable

  chmod +x prune-backup.sh
  ./prune-backup.sh