ubirename: 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

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/sbin/ubirename - from package: mtd-utils

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