- Managing Configuration Files
- Configuration Generation Performance Enhancement
- Exclusive Configuration Change Access and Access Session Locking
- Configuration Replace and Configuration Rollback
- Contextual Configuration Diff Utility
- Configuration Change Notification and Logging
- Configuration Logger Persistency
- Configuration Partitioning
Contents
- Configuration Generation Performance Enhancement
- Finding Feature Information
- Restrictions for Configuration Generation Performance Enhancement
- Information About Configuration Generation Performance Enhancement
- Cisco IOS Software Configuration Storage
- Benefits of the Configuration Generation Performance Enhancement
- How to Configure the Configuration Generation Performance Enhancement
- Configuring the Configuration Generation Performance Enhancement
- Configuration Examples for the Configuration Generation Performance Enhancement
- Configuring the Configuration Generation Performance Enhancement Example
- Verifying the Configuration Generation Performance Enhancement Example
- Additional References
- Feature Information for Configuration Generation Performance Enhancement
Configuration Generation Performance Enhancement
The Configuration Generation Performance Enhancement feature assists configuration management by enabling faster collection of running configuration file information. This feature is especially useful in managing large networks with numerous interfaces configured.
- Finding Feature Information
- Restrictions for Configuration Generation Performance Enhancement
- Information About Configuration Generation Performance Enhancement
- How to Configure the Configuration Generation Performance Enhancement
- Configuration Examples for the Configuration Generation Performance Enhancement
- Additional References
- Feature Information for Configuration Generation Performance Enhancement
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 at the end of this module.
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.
Restrictions for Configuration Generation Performance Enhancement
The device on which the Configuration Generation Performance Enhancement feature is used must have enough memory available to store (cache) a large interface configuration file. For example, if the interface configurations take up 15 KB of memory, using this feature would require having an additional 15 KB of memory space available.
The presence of the parser config cache interface command in the module reflects an improvement in the performance of the configured interfaces. There is no such performance improvement observed in modules without any physical interfaces such as the Network Analyzer Module (NAM).
Information About Configuration Generation Performance Enhancement
- Cisco IOS Software Configuration Storage
- Benefits of the Configuration Generation Performance Enhancement
Cisco IOS Software Configuration Storage
In the Cisco IOS software configuration model, the configuration state is maintained in a distributed manner, with each component storing its own configuration state. To retrieve configuration information, the software must poll every component to collect the distributed information. This configuration state retrieval operation is performed by a process known as nonvolatile generation (NVGEN), and it is used by command-line interface (CLI) commands such as showrunning-config, writememory, and copysystem:running-configuration to display or copy the running system configuration. When invoked, NVGEN queries each system component and each instance of interface or other configuration objects. A running configuration file is constructed as NVGEN traverses the system performing these queries.
 Note | If you try to configure the writememory command when a router is low on memory and the backup buffer cannot be allocated, then the command will fail with the error message, “Not enough space.” When the writememory command fails to apply the new configuration, the backup configuration is used to restore the original configuration. |
Benefits of the Configuration Generation Performance Enhancement
Before the Configuration Generation Performance Enhancement feature was introduced, NVGEN always had to query the entire system and could generate only a total configuration. The time required to process the running configuration creates performance problems for configuration management, because completion of the NVGEN operation can take many minutes.
The Configuration Generation Performance Enhancement feature reduces the execution time for NVGEN processes and is especially useful for managing large configuration files that contain numerous interface configurations. This feature provides faster execution of commands that process the running system configuration by caching interface configuration information in system memory, and by retrieving only configuration information that has changed.
How to Configure the Configuration Generation Performance Enhancement
Configuring the Configuration Generation Performance Enhancement
Perform this task to enable the Configuration Generation Performance Enhancement.
1.
enable
2.
configure
terminal
3.
parser
config
cache
interface
4.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Router> enable |
Enables privileged EXEC mode.
|
| Step 2 |
configure
terminal
Example: Router# configure terminal |
Enters global configuration mode. |
| Step 3 |
parser
config
cache
interface
Example: Router(config)# parser config cache interface |
Reduces the time required for the CLI to execute commands that manage the running system configuration, especially for large configuration files. |
| Step 4 |
end
Example: Router(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Configuration Examples for the Configuration Generation Performance Enhancement
- Configuring the Configuration Generation Performance Enhancement Example
- Verifying the Configuration Generation Performance Enhancement Example
Configuring the Configuration Generation Performance Enhancement Example
The following example shows how to enable the Configuration Generation Performance Enhancement feature:
Router(config)# parser config cache interface
Verifying the Configuration Generation Performance Enhancement Example
You can verify that the parserconfigcacheinterface command has been enabled by checking for the command in the system configuration file displayed when you enter the showrunning-configuration EXEC command.
Note | The first time you display the configuration file, you will not see much evidence of improvement in performance because the interface cache will be filled up. However, you will notice performance improvements when you enter subsequent NVGEN-type commands such as the showrunning-config EXEC command. Each time the interface configuration changes, the cache of the specified interface is flushed. The other interface data remains cached as before. Entering an NVGEN-type command after modifying the interface configuration will once again not show much evidence of improvement until the next NVGEN-type command is entered. |
Router# show running-config ! ! parser config cache interface ! !
Additional References
The following sections provide references related to the Configuration Generation Performance Enhancement feature.
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
System configuration file management commands |
The Cisco IOS Configuration Fundamentals Command Reference appropriate to your software release. |
|
System configuration file management |
“Managing Configuration Files” module in the Cisco IOS Configuration Fundamentals Configuration Guide |
Standards
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Standards |
Title |
|---|---|
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None |
-- |
MIBs
|
MIBs |
MIBs Link |
|---|---|
|
None |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
|
RFCs |
Title |
|---|---|
|
None |
-- |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Feature Information for Configuration Generation Performance Enhancement
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 |
|---|---|---|
|
Configuration Generation Performance Enhancement |
12.3(7)T 12.2(25)S 12.2(33)SRC 12.2(33)SB 12.2(33)SXI |
The Configuration Generation Performance Enhancement feature assists configuration management by enabling faster collection of running configuration file information. This feature is especially useful in managing large networks with numerous interfaces configured. In 12.2(33)SB, this feature was implemented on the Cisco 10000 series. The following command was introduced or modified: parser config cache interface. |