Memory Usage Analyzer; Troubleshooting Global Memory - Cisco CRS-1 - Carrier Routing System Router Troubleshooting Manual

Troubleshooting Global Memory

Memory Usage Analyzer

The memory usage analyzer tool records brief details about the heap memory usage of all processes on
the router at different moments in time and compares the results. This makes it very useful for detecting
patterns of memory usage during events such as restarting processes or configuring interfaces. It is also
useful for troubleshooting memory leaks.
When the memory usage analyzer tool is instructed to take a snapshot, it saves output similar to the show
memory heap summary command output for each process running on the router to a file. When
instructed to show a report, the files are read and the differences between the memory values are
displayed.
The memory usage analyzer tool uses the following commands in sequence:
1.
2.
3.
The command output contains information about each process whose heap memory usage has changed
over the test period. It is ordered by the size of the change, starting with the process with the largest
increase. To detect memory leaks the memory usage analyzer should be used on a stable system when
no configuration changes are taken.
Troubleshooting Global Memory
To begin troubleshooting a router in a low memory state, get a high-level view of where the memory is
being used.
Use the show memory summary command to display system memory information.
RP/0/RP0/CPU0:router# show memory summary
Physical Memory: 4096M total
Application Memory : 3949M (3540M available)
Image: 17M (bootram: 17M)
Reserved: 128M, IOMem: 2028M, flashfsys: 0
Total shared window: 7M
The output shows the amount of physical memory installed on the device, the memory available for the
system to use (total memory minus image size, reserved, and flashfsys), the image size, the reserved
space for packet memory, and the I/O memory used as a backup for packet memory.
If there is not sufficient memory, install more memory. See the Cisco CRS-1 Carrier Routing System
documentation at the following URL:
http://www.cisco.com/en/US/products/ps5763/tsd_products_support_series_home.html
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show memory compare start command—This command takes an initial snapshot of the process
memory usage.
show memory compare end command—This command takes another snapshot of the process
memory usage.
show memory compare report command—This command displays the differences between the
memory values.
Chapter 9 Troubleshooting Memory
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