rpc.rstatd: 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 CentOS possible default full paths are:

/usr/sbin/rpc.rstatd - from package: rusers-server

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

On Debian possible default full paths are:

/usr/sbin/rpc.rstatd - from package: rstatd

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