Upgrade IOS on one unit at a time 9500 stackwise mode!

[Srin_G]

Hello,

Is this possible to be done without an outage?

A pair of cisco 9500 in stackwise virtual mode needs IOS upgrade. I cant afford an outage and I wonder what would be the best way to do it. Initially i thought, I can put the new code in standby bootflash and do a redundancy reload the peer and then do a force switchover for the active unit reload!

The standby boots up with new code after peer reload but wont join the stack because of version mismatch so i cannot do a manual switchover to reboot the active.

Any ideas are appreciated.

regards

[Deepak Kumar]

Hi,

You have been shared very limited information as to what is the current version and what version are you trying?

You can try the ISSU. But make sure you have to read the restrictions and prerequisites for ISSU.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-9/configuration_guide/ha/b_169_ha_9500_cg/configuring_issu_on_stackwise_virtual.html

[Srin_G]

Hi Deepak,

Trying to upgrade from 16.11.1 to 16.12.2

we dont use ISSU or havent tried!

I just put the .bin file into the flash!

regards

[Deepak Kumar]

Hi,

There are very limited options for bundle mode and it is not the recommended mode.

Check the below link for more details (update guide):

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-12/release_notes/ol-16-12-9500.html#id_78572