Linux system backup

backup.sh

  # from https://wiki.archlinux.org/title/Full_system_backup_with_tar
  # -p, --acls and --xattrs store all permissions, ACLs and extended attributes. 
  # Without both of these, many programs will stop working!
  # It is safe to remove the verbose (-v) flag. If you are using a 
  # slow terminal, this can greatly speed up the backup process.
  #--exclude-from=$exclude_file
  tar --exclude=/tmp/* --exclude=/var/tmp/* --exclude=/usr/portage/* --acls --xattrs --one-file-system -cpvf - . | xz -zvv -T3 -0 > file.xz
  
  restore:
  xz | tar --acls --xattrs --numeric-owner -xpf -