As block devices and partitions are detected they are added to a list (128 entry array unless the patch was back-ported). The list is then checked during auto-assembly. It looks like your second controller is not appearing in the list for some reason. You should check earlier messages to see if it's detected at similar times (possibly enable the netconsole logging ( first search hit: http://www.mjmwired.net/kernel/Documentation/networking/netconsole.txt )) and verify the hardware, firmware, and configuration of the second controller match what you expect. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html