debugfs: 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 CentOS possible default full paths are:

/sbin/debugfs - from package: e2fsprogs

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/sbin/debugfs - from package: e2fsprogs
/usr/lib/debug/sbin/debugfs - from package: e2fsprogs-dbg

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

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