humfsify: 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:

/usr/bin/humfsify - from package: uml_utilities

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

On Debian possible default full paths are:

/usr/bin/humfsify - from package: uml-utilities

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

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