Cache Parity Errors - Cisco uBR10012 Troubleshooting Manual

General Information for Troubleshooting Line Card Crashes
Table 4-2
SIG Value
22
23
The vast majority of line card crashes are either Cache Parity Exception (SIG type=20), Bus Error
Step 8
Exception (SIG type=10), and Software-forced Crashes (SIG type=23). Use the following sections to
further troubleshoot these problems:
•
•
•
If the line card crashed for some other reason, capture the output of the show tech-support command.
Registered Cisco.com users can decode the output of this command by using the Output Interpreter tool,
which is at the following URL:
https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl
If you cannot resolve the problem using the information from the Output Interpreter, collect the
Step 9
following information and contact Cisco TAC:
•
•
•
•
For information on contacting TAC and opening a case, see the
on page

Cache Parity Errors

A cache parity error (SIG type is 20) means that one or more bits at a memory location were
unexpectedly changed after they were originally written. This error could indicate a potential problem
with the Dynamic Random Access Memory (DRAM) that is onboard the line card.
Parity errors are not expected during normal operations and could force the line card to crash or reload.
These memory errors can be categorized in two different ways:
•
Cisco uBR10012 Universal Broadband Router Troubleshooting Guide
4-4
SIG Value Types
SIG Name
SIGERROR
SIGRELOAD
Cache Parity Errors, page 4-4
Bus Errors, page 4-5
Software-Forced Crashes, page 4-6
All relevant information about the problem that you have available, including any troubleshooting
you have performed.
Any console output that was generated at the time of the problem.
Output of the show tech-support command.
Output of the show log command (or the log that was captured by your SYSLOG server, if
available).
x.
Soft parity errors occur when an energy level within the DRAM memory changes a bit from a one
to a zero, or a zero to a one. Soft errors are rare and are most often the result of normal background
radiation. When the CPU detects a soft parity error, it attempts to recover by restarting the affected
subsystem, if possible. If the error is in a portion of memory that is not recoverable, it could cause
the system to crash. Although soft parity errors can cause a system crash, you do not need to swap
the board or any of the components, because the problem is not defective hardware.
Chapter 4
Error Reason
Fatal hardware error
Software-forced crash
"Obtaining Technical Assistance" section
Troubleshooting Line Cards
OL-1237-01