iscsi-test-cu: 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/bin/iscsi-test-cu - from package: libiscsi-bin

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

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