I haven't tried ISSU with our VSS pairs but this is about what I expected. Too many caveats to risk it, eh?
Jason -----Original Message----- From: Rob Shakir [mailto:[email protected]] Sent: Friday, February 12, 2010 8:48 AM To: Phil Mayers Cc: Jason Shearer; [email protected] Subject: Re: [c-nsp] ISSU on SXF -> SXI 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 *** NOTICE--The attached communication contains privileged and confidential information. If you are not the intended recipient, DO NOT read, copy, or disseminate this communication. Non-intended recipients are hereby placed on notice that any unauthorized disclosure, duplication, distribution, or taking of any action in reliance on the contents of these materials is expressly prohibited. If you have received this communication in error, please delete this information in its entirety and contact the Amedisys Privacy Hotline at 1-866-518-6684. Also, please immediately notify the sender via e-mail that you have received this communication in error. *** _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
