My company's Windows 2003 R2 SP2 File Server has 5 ISCSI Connected Drives that house 400+ shares. Ranodmly, all shares become inaccessible from the client PC. The UNC path does not work by IP or by Host name. DNS is correct. Administrative Shares (e.g. c$) go down as well. On a reboot the shares come back online and are immediately accessible. 5-10 minutes after reboot the shares are no longer available to the clients. There are no events in the logs to coincide with the shares going down. No warnings, no errors and nothing in information that hint at a problem. The ISCSI connected drives are done so with Microsoft ISCSI Connetor V2.7. The Drives sizes range between 500GB-1000GB.