marc2xml: 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 Debian possible default full paths are:

/usr/bin/marc2xml - from package: libmarc-xml-perl

You may install the required package with command apt-get install {package}

Error in other languages:
marc2xml: bevel nie gevind nie
marc2xml: comandă negăsită
marc2xml: comando não encontrado
marc2xml: commande introuvable
marc2xml: command not found
marc2xml: käsku ei ole
marc2xml: không tìm thấy lệnh
marc2xml: komanda nerasta
marc2xml: Kommando nicht gefunden.
marc2xml: kommandot finns inte
marc2xml: komut yok
marc2xml: nie znaleziono polecenia
marc2xml: níor aimsíodh an t-ordú
marc2xml: no se encontró la orden
marc2xml: no s'ha trobat l'ordre
marc2xml: opdracht niet gevonden
marc2xml: parancs nem található
marc2xml: perintah tidak ditemukan
marc2xml: príkaz nenájdený
marc2xml: příkaz nenalezen
marc2xml: команда не найдена
marc2xml: командата не е открита
marc2xml: 命令找不到
marc2xml: コマンドが見つかりません