ndo2db: 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/sbin/ndo2db - from package: ndoutils-nagios3-mysql

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

Error in other languages:
ndo2db: bevel nie gevind nie
ndo2db: comandă negăsită
ndo2db: comando não encontrado
ndo2db: commande introuvable
ndo2db: command not found
ndo2db: käsku ei ole
ndo2db: không tìm thấy lệnh
ndo2db: komanda nerasta
ndo2db: Kommando nicht gefunden.
ndo2db: kommandot finns inte
ndo2db: komut yok
ndo2db: nie znaleziono polecenia
ndo2db: níor aimsíodh an t-ordú
ndo2db: no se encontró la orden
ndo2db: no s'ha trobat l'ordre
ndo2db: opdracht niet gevonden
ndo2db: parancs nem található
ndo2db: perintah tidak ditemukan
ndo2db: príkaz nenájdený
ndo2db: příkaz nenalezen
ndo2db: команда не найдена
ndo2db: командата не е открита
ndo2db: 命令找不到
ndo2db: コマンドが見つかりません