Administrator Guide

Failure and Event Logging
Dell Networking systems provide multiple options for logging failures and events.
Trace Log
Developers interlace messages with software code to track the execution of a program.
These messages are called trace messages and are primarily used for debugging and to provide lower-level information then event
messages, which system administrators primarily use. Dell Networking OS retains executed trace messages for hardware and software and
stores them in les (logs) on the internal ash.
• NV Trace Log — contains line card bootup trace messages that Dell Networking OS never overwrites and is stored in internal ash
under the directory NVTRACE_LOG_DIR.
• Trace Log — contains trace messages related to software and hardware events, state, and errors. Trace Logs are stored in internal
ash under the directory TRACE_LOG_DIR.
• Crash Log — contains trace messages related to IPC and IRC timeouts and task crashes on line cards and is stored under the directory
CRASH_LOG_DIR.
For more information about trace logs and conguration options, refer to S-Series Debugging and Diagnostics.
Core Dumps
A core dump is the contents of RAM a program uses 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.
• Application core dump is the contents of the memory allocated to a failed application at the time of an exception.
• Kernel core dump 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.
System Log
Event messages provide system administrators diagnostics and auditing information.
Dell Networking OS sends event messages to the internal buer, all terminal lines, the console, and optionally to a syslog server. For more
information about event messages and congurable options, refer to Management.
Hot-Lock Behavior
Dell Networking OS hot-lock features allow you to append and delete their corresponding content addressable memory (CAM) entries
dynamically without disrupting trac. Existing entries are simply shued to accommodate new entries.
Hot-Lock IP ACLs allows you to append rules to and delete rules from an access control list (ACL) 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 about
conguring ACLs, refer to Access Control Lists (ACLs).
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High Availability (HA)