rollctl: 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/rollctl - from package: dnssec-tools

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