Updating firmware (9.26 to 9.31) on MS225 - stacks are leading to network outages while upgrading/rebooting the switches.
I suppose that there is an loop while switch booting and the stackports are in an undefined mode while booting.
Is there any experience how to prevent this?
Would be nice if we could manually push firmware to individual switches starting with the ones the furthest into our network and working back up to the core to avoid this.
There is a function to upgrade switch by switch. But it's hidden, you can ask the support to get it visible.
Then you will find it in the menue "Switch" named "Staged Upgrades".
@redsector this is the feature you are referring to.
Note that if the switches are stacked then all the switches within a stack have to be upgraded and rebooted together at the same time. You can stage switch stacks and non-stacked switches.
My experience is the opposite: upgrading stacked switches step by step, in a staggered upgrade with a time gap of about half an hour has the best results.
Upgrading switches in a stack at the same time leads to unexpected results as loops and spanning-tree issues. I think the reason is while booting the stacked switches the stacking-ports and aggegated links on different switches are in an unconfigured state leading to the described errors.
As I wrote before: you need to tell the hotline to activate it.
Then you will find in your menue this entry to do it: "Switch" - "Staged upgrades".
I have this enabled on my account.
I can select to stage non-stacked switches. It does not allow me to select switches that are part of a stack to stage. I can stage entire switch stacks.
Strange thing. But I did it like described several times.
Once I did it from version 9.26 to 9.31 and later from 9.31 to 10.2 on five stacks with each two MS225-48LP members.
When you upgrade a stack it takes the whole stack out. There is no way around that one.
If it is a network core then I would tend to not stack the switches, Then you will be able to use an upcoming feature that allows you to do staged switch upgrades.