fa2dna: 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/fa2dna - from package: anfo

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

Error in other languages:
fa2dna: bevel nie gevind nie
fa2dna: comandă negăsită
fa2dna: comando não encontrado
fa2dna: commande introuvable
fa2dna: command not found
fa2dna: käsku ei ole
fa2dna: không tìm thấy lệnh
fa2dna: komanda nerasta
fa2dna: Kommando nicht gefunden.
fa2dna: kommandot finns inte
fa2dna: komut yok
fa2dna: nie znaleziono polecenia
fa2dna: níor aimsíodh an t-ordú
fa2dna: no se encontró la orden
fa2dna: no s'ha trobat l'ordre
fa2dna: opdracht niet gevonden
fa2dna: parancs nem található
fa2dna: perintah tidak ditemukan
fa2dna: príkaz nenájdený
fa2dna: příkaz nenalezen
fa2dna: команда не найдена
fa2dna: командата не е открита
fa2dna: 命令找不到
fa2dna: コマンドが見つかりません