tgz: 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/tgz - from package: mtools

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

On Debian possible default full paths are:

/usr/bin/tgz - from package: mtools

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

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