xml_to_db: 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/bin/xml_to_db - from package: perl-Fsdb

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

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