rpc.rwalld: command not found

Have You tried accessing the binary with the full path?

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/rpc.rwalld - from package: rwalld

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