imvirt: 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/imvirt - from package: imvirt

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

On Debian possible default full paths are:

/usr/bin/imvirt - from package: imvirt

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

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