gosa: 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 Debian possible default full paths are:

/usr/share/debian-lan-config/fai/config/files/usr/local/sbin/add2gosa/GOSA - from package: debian-lan-config
/usr/share/debian-lan-config/fai/config/files/usr/local/sbin/gosa-create/GOSA - from package: debian-lan-config
/usr/share/debian-lan-config/fai/config/files/usr/local/sbin/gosa-remove/GOSA - from package: debian-lan-config
/usr/share/debian-lan-config/fai/config/files/usr/local/sbin/gosa-sync/GOSA - from package: debian-lan-config
/usr/bin/gosa - from package: gosa-desktop

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

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