[c-nsp] 4500X in VSS - Upgrading IOS XE

[CiscoNSP List]

Hi Everyone(Sent this to the list yesterday, but it still hasnt shown up?  So re-sending),

I need to upgrade IOS XE on a pair of 4500X's...Id prefer not to try/use ISSU, as they are remote switches and in production....so Im hoping someone has performed an upgrade on these boxes(In VSS) and can provide some guidance on a method that "works" :)

Ive read where people disconnect the VSS link (Or shutdown those ports), and perform the upgrade on the 2 switches, then reconnect VSS....but could you do something like this:

conf reg on both switches is already set to 0x2102, so the switches should honour the bootvar variables

copy new IOS XE to bootflash & slavebootflash

update boot var to point to new XE image

boot system flash bootflash:xxx

wr mem and check bootvar is updated

and reload both switches:

redundancy reload shelf

This should reload both switches, and they should come up with the new image, and VSS should re-establish?

Thanks in advance for any advice/recommendations