S211KENO@HTIKHT5.BITNET (11/12/85)
Security-problem caused by faulty Unibus. We run a VAX 785/785 cluster, both processors connected to an Ethernet and equiped with two Unibus's. Last week DECNET started complaining via OPCOM about the lost Ethernet circuit UNA-0. Also some DHU/port-selector connections were dropped. Operations decided to do a reboot. This did not solve the problem, so remote-diagnosis and field-service were called. They quite soon concluded one Unibus was gone, replaced one board in the DW780 Unibus Adapter and thus solved that problem. The thing that worries me is, that upon the reboot all "floating" comms devices (in our case the DMF32's and the DHU's) in the second, working Unibus were assigned device-names (TXAn TXBn etc) which were normally on the defective one, causing print-output to be spooled to terminals etc. Even worse, users claim these reassignments happened dynamically: without any warning some terminals were connected to someone elses process (before the reboot). Because I cannot reconstruct the situation (can I?) I would appreciate any comments, also, does anyone take special messures to avoid similar situations on an unattended automatic reboot?