Re: OOT: VSS experience

I guess I should elaborate with some information that brings me to that
feeling.

Performing a Fast Software Upgrade of a VSS

The FSU of a VSS is similar to the RPR-based standalone chassis FSU
described in the "Performing a Fast Software Upgrade"
section<http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/redund.html#wpxref62923>.
While the standalone chassis upgrade is initiated by reloading the VSS
standby supervisor engine, the VSS upgrade is initiated by reloading the
VSS standby chassis. During the FSU procedure, a software version mismatch
between the VSS active and the VSS standby chassis causes the system to
boot in RPR redundancy mode, which is stateless and causes a hard reset of
the all modules. As a result, the FSU procedure requires system downtime
corresponding to the RPR switchover time.

This can break the vPC's (not sure if they have same name as Nexus)
and cause some spanning-tree fun if not careful as well. It does need mtnc.
window. Don't forget, this will most likely be distribution/core device
touching almost everything in the campus. Speaking from bloody experience
on that one.

Regards,

Marc

On Thu, Apr 12, 2012 at 6:57 PM, Alexander Halim <cisco.alexand_at_gmail.com>wrote:

> Hi Marc,
>
> Does it mean that VSS requires downtime when doing IOS upgrade? I thought
> it supports eFSU which is a kind of ISSU? Or you are referring to the
> complexity of eFSU procedure?
>
> Thank you for sharing.
>
> Regards,
> Alex
>
> On Apr 12, 2012, at 11:58 PM, marc edwards <renorider_at_gmail.com> wrote:
>
> It is great... but a bitch to update IOS. At least that is my experience
> with it.
>
> On Thu, Apr 12, 2012 at 8:42 AM, Alexander Lim < <cisco.alexand_at_gmail.com>
> cisco.alexand_at_gmail.com> wrote:
>
>> Guys,
>>
>> Sorry for non-technical question.
>> But may I ask you if you have any bad experience deploying/using VSS? Is
>> it
>> quite stable?
>> Would you recommend using VSS in production network?
>>
>> Thanks
>>
>> Regards,
>> Alex
>>
>>
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Received on Thu Apr 12 2012 - 20:07:15 ART