Reference Guide

High Availability | 385
Trace Log
Developers interlace messages with software code to track a the execution of a program. These messages
are called trace messages; they are primarily used for debugging and provide lower level information than
event messages, which are primarily used by system administrators. Dell Networking OS retains executed
trace messages for hardware and software and stores them in files (logs) on the internal flash.
• Trace Log—contains trace messages related to software and hardware events, state, and errors. Trace
Logs are stored in internal flash under the directory TRACE_LOG_DIR.
• Crash Log—contains trace messages related to IPC and IRC timeouts and task crashes on the switch,
and is stored under the directory COREDUMP_DIR.
Core Dumps
A core dump is the contents of RAM being used by a program at the time of a software exception and is
used to identify the cause of the exception. There are two types of core dumps: application and kernel.
• The kernel is the central component of an operating system that manages system processors and
memory allocation and makes these facilities available to applications. A kernel core dump is the
contents of the memory in use by the kernel at the time of an exception.
• An application core dump is the contents of the memory allocated to a failed application at the time of
an exception.
System Log
Event messages provide system administrators diagnostics and auditing information. Dell Networking OS
sends event messages to the internal buffer, all terminal lines, the console, and optionally to a syslog server.
For more information on event messages and configurable options, see Switch Management.
Hot-lock Behavior
Dell Networking OS hot-lock features allow you to append and delete their corresponding CAM entries
dynamically without disrupting traffic. Existing entries are simply are shuffled to accommodate new
entries.
Dell Networking OS offers a Hot-lock feature. Hot-lock ACLs allow you to append rules to and delete
rules from an Access Control List that is already written to CAM. This behavior is enabled by default and
is available for both standard and extended ACLs on ingress and egress. For information on configuring
ACLs, see Access Control Lists (ACLs).