lockfs-notify: 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 Debian possible default full paths are:

/usr/bin/lockfs-notify - from package: bilibop-lockfs

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

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