convertar: 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

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/convertar - from package: dnssec-tools

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