Core Issue
This is due to a lack of available memory caused by insufficient physical memory or a memory leak.
Resolution
If no output is produced when the show run command is issued, perform the following steps:
- Issue the show memory [summary] command to see how much free process memory is available as well as the size of the largest free contiguous memory block.
router#show memory summary
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 616970C0 9867072 8746428 1120644 37076 58144
Fast 616770C0 131080 74616 56464 56464 56412
In the previous example, the free processor memory is more than 1MB (1,120,644 bytes) but the largest memory block is only about 58K (58144 bytes).
This indicates the memory is fragmented. This may be caused by a bug. If either the Free(b) or the Largest(b) numbers are low, the show run command output may not be produced due to a lack of available memory to process the command.
- Check the logs for %SYS-2-MALLOCFAIL error messages by issuing the show logging command. Note: If logging is enabled for the terminal session, the %SYS-2-MALLOCFAILmessage may show up when the show run command is issued.
router#show logging
Syslog logging: enabled (0 messages dropped, 0 flushes, 0 overruns)
Console logging: disabled
Monitor logging: level debugging, 0 messages logged
Buffer logging: level informational, 280 messages logged
Trap logging: level informational, 1259 message lines logged
Logging to 159.161.30.53, 1259 message lines logged
Logging to 143.91.102.84, 1259 message lines logged
If the %SYS-2-MALLOCFAIL errors are present, refer to Troubleshooting Memory Problems. This is also useful for determining whether the issue is caused by a lack of physical memory or a software issue.
If a memory leak or other bug is causing the issue, upgrade the Cisco IOS Software to a version in which the issue is resolved.
If the router does not have enough physical memory, either add memory or change to a version of Cisco IOS Software with a lower memory requirement.
In cases where a memory leak is present, a temporary workaround may be to reload the router.
