On 12 Feb 2010, at 12:29, Phil Mayers wrote: > * The old and new image are not ISSU-compatible (different major releases or > feature sets) - in which case an RPR upgrade is the best you can do. > > * The old and new images are ISSU compatible, and the linecard software has > not changed. In this case, the linecards do not need to be restarted, and > downtimes of 0-3 seconds can be achieved because it's basically just an SSO > switchover. > > * The old and new images are ISSU compatible but the linecard software is > different, so the linecards need to be restarted into the new image - this > can be a faster, warm boot (if the linecard has enough RAM) or a slower, cold > boot (if not) > > I think that's about right?
This seems quite accurate to me. Our experience of ISSU has been terrible. We've found multiple bugs related to it, and have found that -- in general -- we're much better off in terms of service disruption with a "classic" upgrade (upgrade secondary, reload peer, force failover, etc). Cisco advised us that it is unlikely that ISSU on 7600/6500 will meet our requirements, and hence we are better off doing classic upgrades. We've taken their advice, and will not be trying it again. I think it's suited for deployments where you have 30+ boxes that are identical in terms of configuration, and hardware, but in the SP environment (like us), the variance of boxes means that it's just not worthwhile. Kind regards, Rob -- Rob Shakir <[email protected]> Network Development Engineer GX Networks/Vialtus Solutions ddi: +44208 587 6077 mob: +44797 155 4098 pgp: 0xc07e6deb nic-hdl: RJS-RIPE This email is subject to: http://www.vialtus.com/disclaimer.html _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
