orbit-name-server-2: 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/orbit-name-server-2 - from package: orbit2-nameserver

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

Error in other languages:
orbit-name-server-2: bevel nie gevind nie
orbit-name-server-2: comandă negăsită
orbit-name-server-2: comando não encontrado
orbit-name-server-2: commande introuvable
orbit-name-server-2: command not found
orbit-name-server-2: käsku ei ole
orbit-name-server-2: không tìm thấy lệnh
orbit-name-server-2: komanda nerasta
orbit-name-server-2: Kommando nicht gefunden.
orbit-name-server-2: kommandot finns inte
orbit-name-server-2: komut yok
orbit-name-server-2: nie znaleziono polecenia
orbit-name-server-2: níor aimsíodh an t-ordú
orbit-name-server-2: no se encontró la orden
orbit-name-server-2: no s'ha trobat l'ordre
orbit-name-server-2: opdracht niet gevonden
orbit-name-server-2: parancs nem található
orbit-name-server-2: perintah tidak ditemukan
orbit-name-server-2: príkaz nenájdený
orbit-name-server-2: příkaz nenalezen
orbit-name-server-2: команда не найдена
orbit-name-server-2: командата не е открита
orbit-name-server-2: 命令找不到
orbit-name-server-2: コマンドが見つかりません