service_set_value: 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:

/lib/rc/bin/service_set_value - from package: openrc

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

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