gsa: 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/gsa - from package: gwenhywfar-devel

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

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