selfserv: 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/selfserv - from package: libnss3-tools

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

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