virt-log: 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/virt-log - from package: libguestfs-tools

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

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