NonStop NS14000 Planning Guide (H06.10+)

In the event of a processor fault in either a duplex or triplex processor, the failed component
within a NonStop Blade Element (processor element, power supply, and so forth) or the entire
Blade Element can be replaced while the system continues to run. A single Integrity NonStop
NS14000 system can have up to two NonStop Blade Complexes for a total of eight processors.
Processors communicate with each other and with the system I/O over dual ServerNet fabrics.
In the term ServerNet fabric, the word fabric is significant because it contrasts with the concept
of a bus. A bus provides a single, fixed communications path between start and end points. A
fabric is a complex web of links between electronic routers that provide a large number of possible
paths from one point to another. Two communications fabrics, the X and Y ServerNet, provide
redundant, fault-tolerant communications pathways. If a hardware fault occurs on one of the
ServerNet fabrics, communication continues on the other with hardware fault recovery transparent
to all but the lowest level of the OS.
Input/output components tap into the ServerNet fabrics through Fibre Channel and Ethernet
ServerNet functionality in the VIO enclosures in the preceding diagram of the NSAA. The Fibre
Channel and Ethernet functionality in the VIO enclosures provides the system I/O to Fibre
Channel storage devices and gigabit Ethernet communications networks.
Although the hardware architecture differs from one series of NonStop servers to another, the
Integrity NonStop NS14000 system can be networked with other NonStop systems using the
same message system and the same network software.
36 Integrity NonStop NS14000 System Description