euare-groupmod: 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/euare-groupmod - from package: euca2ools

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

On Debian possible default full paths are:

/usr/bin/euare-groupmod - from package: euca2ools

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

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