afs5log: 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/bin/afs5log - from package: pam_krb5

You may install the required package with command yum install {package}
Error in other languages:
afs5log: bevel nie gevind nie
afs5log: comandă negăsită
afs5log: comando não encontrado
afs5log: commande introuvable
afs5log: command not found
afs5log: käsku ei ole
afs5log: không tìm thấy lệnh
afs5log: komanda nerasta
afs5log: Kommando nicht gefunden.
afs5log: kommandot finns inte
afs5log: komut yok
afs5log: nie znaleziono polecenia
afs5log: níor aimsíodh an t-ordú
afs5log: no se encontró la orden
afs5log: no s'ha trobat l'ordre
afs5log: opdracht niet gevonden
afs5log: parancs nem található
afs5log: perintah tidak ditemukan
afs5log: príkaz nenájdený
afs5log: příkaz nenalezen
afs5log: команда не найдена
afs5log: командата не е открита
afs5log: 命令找不到
afs5log: コマンドが見つかりません