zonetodb: 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/sbin/zonetodb - from package: bind-sdb

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