ps2raster: 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/ps2raster - from package: GMT

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

On Debian possible default full paths are:

/usr/lib/gmt/bin/ps2raster - from package: GMT

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

Error in other languages:
ps2raster: bevel nie gevind nie
ps2raster: comandă negăsită
ps2raster: comando não encontrado
ps2raster: commande introuvable
ps2raster: command not found
ps2raster: käsku ei ole
ps2raster: không tìm thấy lệnh
ps2raster: komanda nerasta
ps2raster: Kommando nicht gefunden.
ps2raster: kommandot finns inte
ps2raster: komut yok
ps2raster: nie znaleziono polecenia
ps2raster: níor aimsíodh an t-ordú
ps2raster: no se encontró la orden
ps2raster: no s'ha trobat l'ordre
ps2raster: opdracht niet gevonden
ps2raster: parancs nem található
ps2raster: perintah tidak ditemukan
ps2raster: príkaz nenájdený
ps2raster: příkaz nenalezen
ps2raster: команда не найдена
ps2raster: командата не е открита
ps2raster: 命令找不到
ps2raster: コマンドが見つかりません