debugfs.reiser4: 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:

/sbin/debugfs.reiser4 - from package: reiser4progs

You may install the required package with command apt-get install {package}
Error in other languages:
debugfs.reiser4: bevel nie gevind nie
debugfs.reiser4: comandă negăsită
debugfs.reiser4: comando não encontrado
debugfs.reiser4: commande introuvable
debugfs.reiser4: command not found
debugfs.reiser4: käsku ei ole
debugfs.reiser4: không tìm thấy lệnh
debugfs.reiser4: komanda nerasta
debugfs.reiser4: Kommando nicht gefunden.
debugfs.reiser4: kommandot finns inte
debugfs.reiser4: komut yok
debugfs.reiser4: nie znaleziono polecenia
debugfs.reiser4: níor aimsíodh an t-ordú
debugfs.reiser4: no se encontró la orden
debugfs.reiser4: no s'ha trobat l'ordre
debugfs.reiser4: opdracht niet gevonden
debugfs.reiser4: parancs nem található
debugfs.reiser4: perintah tidak ditemukan
debugfs.reiser4: príkaz nenájdený
debugfs.reiser4: příkaz nenalezen
debugfs.reiser4: команда не найдена
debugfs.reiser4: командата не е открита
debugfs.reiser4: 命令找不到
debugfs.reiser4: コマンドが見つかりません