lslocks: 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/lslocks - from package: util-linux

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

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