First you need to log into compellent enterprise manager. Next select the cluster you want to generate diagnostics for and select the systems tab select internal then select the diagnostics you wish to run then select run diagnostics. Once you select OK the diagnostics will run if configured the diagnostics will automatically be sent to phone home.
If it is not configured you will have to access it through an FTP service. Once your report is generated you need to log into the FTP service running on the NAS controller to retrieve it enter the FTP address from the report summary and your NAS login shown here is a pre generated report for demonstration. Once logged in open diagnostics then archive then general system diagnostic.