krb5kdc: 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 CentOS possible default full paths are:

/usr/sbin/krb5kdc - from package: krb5-server

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

On Debian possible default full paths are:

/usr/sbin/krb5kdc - from package: krb5-kdc

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

Error in other languages:
krb5kdc: bevel nie gevind nie
krb5kdc: comandă negăsită
krb5kdc: comando não encontrado
krb5kdc: commande introuvable
krb5kdc: command not found
krb5kdc: käsku ei ole
krb5kdc: không tìm thấy lệnh
krb5kdc: komanda nerasta
krb5kdc: Kommando nicht gefunden.
krb5kdc: kommandot finns inte
krb5kdc: komut yok
krb5kdc: nie znaleziono polecenia
krb5kdc: níor aimsíodh an t-ordú
krb5kdc: no se encontró la orden
krb5kdc: no s'ha trobat l'ordre
krb5kdc: opdracht niet gevonden
krb5kdc: parancs nem található
krb5kdc: perintah tidak ditemukan
krb5kdc: príkaz nenájdený
krb5kdc: příkaz nenalezen
krb5kdc: команда не найдена
krb5kdc: командата не е открита
krb5kdc: 命令找不到
krb5kdc: コマンドが見つかりません