lockfile-remove: 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/lockfile-remove - from package: lockfile-progs

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

On Debian possible default full paths are:

/usr/bin/lockfile-remove - from package: lockfile-progs

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

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