CSM upgrade in the ft situation

[HWangLoyalty_2]

There are two separate Cat6513 chassis each contain a CSM.We configured as active/standby mode. In future, we will upgrade image of CSM from 4.2(3) to 4.2 (11). After I finish upgrade image and reboot the standby one,

My question is if the A/S mode could be generated because of different image at that time?

Through the CSM configurationguide 4.2 from Cisco website, I found the topic "Configuring a Hitless Upgrade". Another question is when we will reboot the active CSM. Until old standby one is online?

Please advice. Thanks a lot first.

[htarra]

It supports synchronizing the configuration between the active and the standby CSM over the fault-tolerant VLAN. While the active CSM is rebooting the standby CSM will take over and become active. If you've configured the active CSM with a higher priority and preempt that it would become active after reboot otherwise the standby will stay active.