fastDNAml: 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 Debian possible default full paths are:

/usr/bin/fastDNAml - from package: fastdnaml

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