sdiag: 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/sdiag - from package: slurm-client

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

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