Catalyst 9500 stackwise and issu 16.8.1 to 16.9.1

[hnzl]

As the title states.. 

is it possible even to do an issu upgrade while having 2 9500's in stackwise virtual (running 16.8.1) and try to update it to 16.9.1?

So far when trying it just brakes everything :-)

followed this guide to no avail.
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-8/configuration_guide/ha/b_168_ha_9500_cg/b_168_ha_9500_cg_chapter_0100.html

[Leo Laohoo]

I personally don't recommend ISSU, FSU/eFSU.

[paul driver]

Hello Leo

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@Leo Laohoo wrote:
I personally don't recommend ISSU, FSU/eFSU.

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Having myself not even touched cat9ks I would be very interested on your views regards this if applicable ?

[Leo Laohoo]

ISSU, FSU/eFSU is a complicated method of upgrading the IOS using a semi-automated script.
If the switches/chassis are in an "ideal" position, ISSU, FSU/eFSU is a wonder. However, I haven't had any luck with them. And when it fails to work, the VSS pair will take turn rebooting. I found that doing the upgrade the "old fashion way" works all the time.
Most of the time, if I see thread about ISSu/FSU/eFSU it means it didn't work.
With the dawning of DNA-C, I don't believe issues with ISSU, FSU/eFSU will be fixed or improved.

Happy to hear comments from people who've used ISSU/FSU/eFSU.

[paul driver]

Cheers Leo 

tbh I have only every done issu on dell and juniper stacks which may I say worked okay - If I was requested to perform an 9k stack upgrade at this time I would straight away in all honestly think to go via installing the software on each member and reloading it manually like the other cisco stacks I have completed