backup-takedown: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/backup-takedown - from package: chiark-backup

You may install the required package with command apt-get install {package}

Error in other languages:
backup-takedown: bevel nie gevind nie
backup-takedown: comandă negăsită
backup-takedown: comando não encontrado
backup-takedown: commande introuvable
backup-takedown: command not found
backup-takedown: käsku ei ole
backup-takedown: không tìm thấy lệnh
backup-takedown: komanda nerasta
backup-takedown: Kommando nicht gefunden.
backup-takedown: kommandot finns inte
backup-takedown: komut yok
backup-takedown: nie znaleziono polecenia
backup-takedown: níor aimsíodh an t-ordú
backup-takedown: no se encontró la orden
backup-takedown: no s'ha trobat l'ordre
backup-takedown: opdracht niet gevonden
backup-takedown: parancs nem található
backup-takedown: perintah tidak ditemukan
backup-takedown: príkaz nenájdený
backup-takedown: příkaz nenalezen
backup-takedown: команда не найдена
backup-takedown: командата не е открита
backup-takedown: 命令找不到
backup-takedown: コマンドが見つかりません