Compaq ProLiant 8000 Compaq ProLiant NMI Crash Dump Feature - Page 3

Compaq ProLiant Server NMI Crash Dump Feature 3 What Is NMI Crash Dump Non-Maskable Interrupt (NMI) Crash Dump is a diagnostic mechanism. It allows for crash dump files to be created in situations when a system is hung and not able to respond to traditional debug mechanisms. Crash dump analysis is an essential part of diagnosing reliability problems such as hangs in operating systems, device drivers, and applications. Many crashes will freeze a system in such a way that your only recourse is to do a hard reset-(i.e. power cycle the system). Since resetting the system erases any information that would support an analysis of the problem, it is desirable for the system to be able to perform a memory dump before a hard reset is performed. A dump switch and the associated support in Windows NT, Windows 2000, NetWare, SCO OpenServer 5, and SCO UnixWare 7 provide this function. Figure 1: NMI Crash Dump Issue Resolution Events The dump switch can be used to diagnose software failures by forcing the operating system to invoke the non-maskable interrupt (NMI) handler and generate a crash dump log. The crash dump log can provide critical information for root-cause analysis that may be difficult or impossible to obtain through other means A user initiates a Non Maskable Interrupt (NMI) event by pressing the dump switch. The NMI can allow a hung system to become responsive enough to generate a crash dump log. WARNING: Using the NMI Crash Dump switch on a functioning system (using any operating system) will cause the unit to abruptly fail. This is the designed functionality of the NMI Crash Dump Switch. Thus, is should never be used during normal operation. Compaq has enhanced Automatic Server Recovery (ASR) handling for situations where an automated crash dump may be desired. ASR detects a lockup and normally provides a system reset. ASR can be configured to generate the Crash Dump NMI instead of a reset. This will allow for a crash dump file to be written prior to a system reset. The Compaq health (systems management) driver must be loaded in order to properly differentiate an NMI caused by the dump switch from a PCI SERR NMI. The dump switch operates even if the health driver is not loaded. The NMI Crash Dump switch may not work in all situations: after another NMI has already occurred in the system, when the OS crash handler is incapable of running properly, following some hardware failures, and when ASR is in progress, for example. 11N8-0100A-WWEN