Extreme Networks ExtremeWare Version 7.8 Troubleshooting Manual page 39

switch is equipped with MSM-64i modules), or 2) initiate a hitless failover (when the switch is
equipped with MSM-3 modules). The watchdog is a software watchdog timer that can be enabled or
disabled through CLI commands. The watchdog timer is reset as long as ExtremeWare is functioning
well enough to return to the main software exception handling loop where the critical software
exception handling tasks, such as tBGTask, handle the process of resetting the watchdog timer and
creating log entries.
• Software configuration settings for the system health check feature, or for any of the diagnostic tests
that you might choose to run manually.
For example, in the context of memory scanning and mapping,
three tables that describe the behavior of the switch for different platform types and diagnostics
configuration:
Table 6:
—
— Table 7:
— Table 8:
NOTE
On switches equipped with MSM64i modules, you should periodically use the
to ensure that the slave MSM and master MSM are using matched images and configurations. If not
synchronized, the slave MSM might attempt to use the image it has loaded in conjunction with the
configuration from the master MSM, a mismatch that will most likely cause the switch to behave
differently after an MSM failover, thereby defeating the intended purpose of redundant peer MSMs.
The significance in the MSM failover behavior is that is affected by, and affects the use of the
diagnostics, and can also affect and be affected by the way you configure the software exception
handling options such as the system watchdog, system recovery level, and reboot loop protection. For
example, if you select the "shutdown" option in the
the actions the software routine performs is to instruct the slave MSM in a BlackDiamond switch not to
monitor the master MSM, to prevent MSM failover from occurring.
NOTE
The MSM-3 uses technology that provides "hitless" failover, meaning the MSM-3 transitions through a
failover with no traffic loss and no switch downtime, while it maintains active links and preserves layer 2
state tables. Contrast this performance to the failover process of MSM64i modules, which can take the
switch down for approximately 30 seconds. The MSM-3 makes hitless upgrades possible. It is supported
in ExtremeWare release 7.1.1 and later.
Advanced System Diagnostics and Troubleshooting Guide
Auto-recovery memory scanning and memory mapping behavior
Manual diagnostics memory scanning and memory mapping behavior, normal
Manual diagnostics memory scanning and memory mapping behavior, extended
Overview of Software Exception Handling Features
Chapter 5, "Diagnostics," contains
configure sys-recovery-level
command
synchronize
command, one of
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