Fault tolerant network server having multiple slideably-mounted processing elements sharing a redundant array of independent disks through SCSI isolators

A fault-tolerant network server comprising:

• a first processing unit coupled to receive power through a first power cord, the processing unit comprising at least one CPU,
• system memory coupled to the at least one CPU, an interface for a RAID system and addressable by the at least one CPU,
• at least one disk drive addressable by the at least one CPU, a network interface addressable by the at least one CPU, and
• a case containing said at least one CPU, system memory, interface for a RAID system, network interface, and disk drive;
• a second processing unit coupled to receive power through a second power cord, the processing unit comprising a case,
• at least one CPU disposed within the case,
• system memory coupled to the at least one CPU and disposed within the case,
• an interface for a RAID system addressable by the at least one CPU and disposed within the case,
• a network interface addressable by the at least one CPU and disposed within the case,
• at least one disk drive addressable by the at least one CPU and disposed within the case, and
• a power supply disposed within the case, coupled to energize the CPU, system memory, interface for a RAID system, network interface, and disk drive;
• a RAID system coupled to receive power both through the first power cord and the second power cord, said RAID system coupled to the first processing unit and to the second processing unit including a shelf for mounting hot-pluggable disk drives, a first RAID controller coupled to said shelf and to the first processing unit and a second RAID controller coupled to said shelf and to the second processing unit, wherein the first RAID controller is coupled to said shelf for mounting hot-pluggable disk drives through a first isolation circuit, and wherein the second RAID controller is coupled to said shelf for mounting hot-pluggable disk drives through a second isolation circuit, and wherein the first and the second isolation circuits each include a manually activated disable switch that, when in a disable setting, causes the isolation circuit to block all transactions between a RAID controller and a processing unit, a connection present detection circuit that, when a processing unit connection cable is detected as being disconnected from the isolation circuit, causes the isolation circuit to block all transactions between the RAID controller and the processing unit connection cable, and an activity monitor that creates a visual indication of transactions between the processing unit and the RAID controller;
• and
• a network server case, the case of each of the first and second processing units being slideably mounted within the network server case, and the RAID system being disposed within the network server case.