cacertdir_rehash: 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/cacertdir_rehash - from package: authconfig

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

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