virtlockd: 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/lib/debug/usr/sbin/virtlockd - from package: libvirt0-dbg
/usr/sbin/virtlockd - from package: libvirt-daemon

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

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