[c-nsp] Warm reload in Cisco 6500

[Phil Mayers]

On 01/03/2011 12:04 PM, Grzegorz Janoszka wrote:
>
> There is a nice feature in Cisco IOS:
> http://www.cisco.com/en/US/docs/ios/fundamentals/configuration/guide/warm_reload.html
>
> According to Cisco software advisor (Find software with the features I
> need), it is available in 12.2 for C6500/SUP720 in all releases of
> trains SXH and SXI.

I think software advisor is incorrect (big surprise). Warm Reload is not 
available on this platform I'm pretty sure.

If you have two supervisors you can "emulate" it with RPR+ mode. However 
when you force a switchover you still have 30-90 seconds of outage as 
your linecards reload, dependent on your linecard mix and configured 
features.

There is also eFSU in later versions of IOS, giving 0-3 seconds outage 
if you have enough RAM on the linecards, but I'm not sure if you could 
(ab)use that to reload into the same IOS version; the argument to "issu 
loadversion" probably needs to be a different IOS than the running one?

And of course both involve the expense of a 2nd SUP, which is why Cisco 
aren't incentivised to implement warm reload - their way, you spend more 
money!