iscsi-test: 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/iscsi-test - from package: libiscsi-utils

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

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