cdbackup: 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 CentOS possible default full paths are:

/usr/bin/cdbackup - from package: cernlib-packlib

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/cdbackup - from package: cdbackup

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

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