Most likely the problem is in the switch/network setup.  Try configuring the array using the serial cable connected to the active control module.  Also, go to this link and follow each step to ensure you have all the components configured properly:

en.community.dell.com/.../3615.rapid-equallogic-configuration-portal-by-sis.aspx

-joe

Hi Joe

Thanks for you reply... do you know any configuration details about Power connect 8024

Thanks in advance

The configuration for the 8024F is listed on the link I provided (but it's a little hard to see, look for the "SAN switch reference architectures" link).  In any event, here is the URL it points to:

en.community.dell.com/.../3590.san-switch-reference-architectures-by-sis.aspx

-joe