ACI Spine Upgrade - Lost time/date

[hpcs]

I just started upgrading my ACI fabric from 4.2(6H) to 4.2(7S) and have had an interesting bug. I upgraded my APICs with no issue to 4.2(7S). I then tried to upgrade my spines (9508) one at a time via the gui. No issue with compatibility checks prior to upgrade. Upgrade seemed fine but after 30 minutes the node had not come back online post upgrade reboot. I consoled into the device and found the device had yet to download its configuration from the APICs. The upgrade itself completed successfully, but it was just sitting without any configuration beside TEP address and hostname. A "showdiscoveryissue" resulted in a failure at check09 "SSL check [fail] error ssl certificate is vaild (and a 2019 date)". When I ran "show clock" on the device it came back with a date of 2013... I was unable to change the date manually and had to call Cisco in order to get root access to the device. Once I changed the date, the device downloaded a config and joined the fabric in a matter of seconds. 

Any thoughts on this from the community? I've need to upgrade my other spine in the near future but want to get an understanding of what might have happened here. 

Thanks 

[Robert Burns]

Since you have a TAC case already open, and they likely have access to the pre/post upgrade logs they should be able to give you either a known bug ID, or some form of RCA.  If not I would pursue this since you have additional spines to upgrade.  

Are these dual sup 9508s?

Robert

[hpcs]

They are dual sup 9508s. Looking through the logs myself, I saw no issues related to the upgrades. Hoping they come back with something quickly. 

In your opinion, how long can I stay in a mismatched version state on these two spines? 

Thanks

[Robert Burns]

As long as you're not making any drastic infra changes or deploying new features, you shouldn't have any issues running the two versions for a month or more.  

Robert