klogind: command not found

Have You tried accessing the binary with the full path?

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/kerberos/sbin/klogind - from package: krb5-appl-servers

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