Upgrade Catalyst 6807xl Sup6T VSS cluster; 15.4(1)SY2->15.5(1)SY1

[faizan.khan]

Planning to upgrade our Cisco Catalyst 6807xl Sup6T VSS clusters 15.4 (1) SY2-> 15.5 (1) SY1
Can we do it with ISSU or eFSU to get as little interruption as possible?
Finds no information about it when I go from 15.4 (1) SY2-> 15.5 (1) SY1

[balaji.bandi]

Personally i do not recommend ISSU or eFSU , my experience some failures in production environment.

Best way to use IOS upgrade in 6807xl without ISSU - no downtime required but recommended to do it in maintenance window

reference :

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/15-3SY/config_guide/sup6T/15_3_sy_swcg_6T/virtual_switching_systems.html#16572