find-large-clusters: 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/find-large-clusters - from package: dnaclust

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