sleepd: 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/sleepd - from package: sleepd

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

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