What is difference between "copy run nvram" and "commit" in ASR9K?

[wfqk]

Hi 

What is difference between "copy run nvram" and commit in ASR9K when "copy run nvram" under general mode and "commit" under config mode?

Thank you

[Georg Pauwen]

Hello,

basically, IOS XR consists of two stages, the target configuration stage, and the commit stage. When you 'commit' your configuration, it becomes part of the running configuration. The document below explains it pretty well:

Understanding "commit" command In IOS XR

https://supportforums.cisco.com/document/12015521/understanding-commit-command-ios-xr

'Copy run nvram' makes the running config the startup config.

[Julio E. Moisa]

Hi

I agree with Georg explanation, basically you can make any change on the ASR device but it will take effect only if you execute the commit command line.

My 2 cents

:-)

[wfqk]

Thanks for your reply. 

I think after we use command "commit", we do not need to use any other commands like "copy run nvram", right? Although command  "copy run nvram" exists in asr9k, it is almost no useful in asr9k, do you agree? 

[Julio E. Moisa]

Hi,

Yes, that's correct, the following link could be useful:

http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-1/system_management/command/reference/b_sysman_cr41asr9k/b_sysman_cr41asr9k_chapter_0110.pdf

Also you can use the command: configuration commit auto-save Filename

I have used copy running-config filename or location, to build a file with the configuration for backup purposes, but this action could generate CPU utilization.

:-)

[wfqk]

In regular IOS, the configuration for whole router is saved on nvram. When it reboots, the configuration enter ram from nvram. In XR, can we think it is the same procedure as the regular IOS?　My understanding is the command "commit" only can add all commands to running-config at one time point. but the new added commands are also saved at nvram. So command "copy run nvram" is no useful in asr9k because it has commad "commit". but i think the command "copy running location" you mentioned is very useful

[Julio E. Moisa · Accepted solution]

Hi

The commit command will save the configuration on the running-config, it also is useful to mark rollback points. For example a configuration was applied and it generated network problems, you could go back to a previous config. You can see the rollback points executing show rollback points.

Now copy running-config location is useful for example if you want to save the current configuration to a Tftp server.

:-)

[wfqk]

I mean command "copy run nvram" is no useful in asr9k since it has command "commit", do you agree? thanks

[Julio E. Moisa]

Hi

That's correct. 

:-)

[wfqk]

Thank you!

[Julio E. Moisa]

You are welcome,

Thank you 

Have a great day!