gpmetis: 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/gpmetis - from package: metis

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

On Debian possible default full paths are:

/usr/bin/gpmetis - from package: metis

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

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