It's fixed - and here's how. The servers are running nehalem chips with banks of memory per chip. To run in advanced ecc mode required sticks of memory fanning out in channels identified alphabetically - A, B, C and so forth. It seems when the server was shipped they'd put one of the sticks in the wrong slot. Once all were set correctly the OS booted just fine. So whoever said check how the memory is seated in an earlier response thanks very much ! And thanks to all others for their advice also of course. -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines