debugvmfs: 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/sbin/debugvmfs - from package: vmfs-tools

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