Memory Threshold
Notifications
The Memory Threshold Notifications feature allows you to reserve memory for critical notifications and to configure a router to issue notifications when available memory falls below a specified threshold.
- Finding Feature Information
- Information About Memory Threshold Notifications
- How to Define Memory Threshold Notifications
- Configuration Examples for Memory Threshold Notifications
- Additional References
- Feature Information for Memory Threshold Notifications
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About Memory Threshold Notifications
The Memory Threshold Notifications feature provides two ways to mitigate low-memory conditions on a router: notifications can be sent to indicate that free memory has fallen below a configured threshold, and memory can be reserved to ensure that sufficient memory is available to issue critical notifications. To implement the Memory Threshold Notifications feature, you should understand the following concepts:
Memory Threshold Notifications
The Memory Threshold Notifications feature allows you to reserve memory for critical notifications and to configure a router to issue notifications when available memory falls below a specified threshold.
Memory Reservation
Memory reservation for critical operations ensures that management processes, such as event logging, continue to function even when router memory is exhausted.
How to Define Memory Threshold Notifications
Setting a Low Free Memory Threshold
Perform this task to set a low free memory threshold.
1.
enable
2.
configure
terminal
3.
memory
free
low-watermark
[processor threshold
DETAILED STEPS
Reserving Memory for Critical Notifications
When a router is overloaded by processes, the amount of available memory might fall to levels insufficient for it to issue critical notifications. Perform this task to reserve a region of memory to be used by the router for the issuing of critical notifications.
1.
enable
2.
configure
terminal
3.
memory
reserve
critical
kilobytes
DETAILED STEPS
Configuration Examples for Memory Threshold Notifications
Setting a Low Free Memory Threshold Examples
Threshold for Free Processor Memory
The following example shows how to specify a threshold of 20000 KB of free processor memory before the router issues notifications:
Router(config)# memory free low-watermark processor 20000
If available free memory falls below the specified threshold, the router sends a notification message like this one:
000029: *Aug 12 22:31:19.559: %SYS-4-FREEMEMLOW: Free Memory has dropped below 20000k Pool: Processor Free: 66814056 freemem_lwm: 204800000
Once available free memory rises to above 5 percent of the threshold, the router sends a notification message like this one:
000032: *Aug 12 22:33:29.411: %SYS-5-FREEMEMRECOVER: Free Memory has recovered 20000k Pool: Processor Free: 66813960 freemem_lwm: 0
Reserving Memory for Critical Notifications Example
The following example shows how to reserve 1000 KB of memory for critical notifications:
Router# memory reserved critical 1000
 Note | The amount of memory reserved for critical notifications cannot exceed 25 percent of total available memory. |
Additional References
For additional information related to the CPU Thresholding Notification feature, refer to the following references:
Related Documents
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Related Topic |
Document Title |
|---|---|
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SNMP traps |
Configuration Fundamentals Command Reference |
Standards
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Standards |
Title |
|---|---|
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No new or modified standards are supported by this feature and support for existing standards has not been modified by this feature. |
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MIBs
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MIBs |
MIBs Link |
|---|---|
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CISCO-PROCESS-MIB |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
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RFCs |
Title |
|---|---|
|
No new or modified RFCs are supported by this feature and support for existing RFCs has not been modified by this feature. |
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Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for Memory Threshold Notifications
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.|
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
Memory Threshold Notifications |
Cisco IOS XE Release 2.1 |
This feature was introduced on Cisco ASR 1000 Series Aggregation Services Routers. |
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