Summit Stack hitless upgrade

[Thomas_Hilber]

Hi guys,
I have a stack with two x480 running XOS 15.3.1.4
Is it possible to upgrade the two switches in the stack one after another so that one of the switches is allways forwarding traffic?
Thanks,
Thomas

[treese]

So there's no scenario where one switch can stay active while the other one reboots and installs the new image? I've worked with Extreme for quite sometime but we are starting to use stacking more often. We stack to keep our uplinks or downlinks active when a switch in the stack fails traffic isn't re-routed. Its seems like I should be able to unstack one while we upgrade then re stack it. Might be too much trouble though. The ideal situation is a hitless upgrade. Otherwise I've got to notify members who terminate to this stack that there will in fact be downtime.

[Drew_C]

During the upgrade installation, network traffic will continue as usual. The only time your traffic should need to "failover" is when you decide to reboot the stack to complete the upgrade.

[treese]

This is the part I need the detail on " You can update the stacks separately so that you can failover from one stack to the other" I want my traffic to fail over to other switch while the upgrade is going on the first one in the stack.

[Drew_C]

Hi Ted,
Take a look at this article to see if it helps to answer some of your questions: How to upgrade EXOS on a Summit Stack

In short, you'll be installing EXOS to the inactive partition of each switch in the stack. When you reboot the stack, all switches will come up on that newly installed version. You can't mix running and active versions in different nodes or switches in a stack. They MUST be the same across the stack. You can update the stacks separately so that you can failover from one stack to the other.

[Stephane_Grosj1]

Hi Thomas,

If you stay on a patch level upgrade (15.3.1p1-10 to 15.3.1p1-41), you should be able to upgrade one stack member at a time. That's not ISSU, but more like Rolling Upgrade. Put the image on one member, reboot it. When it's back and operational, do the same for the other. So really, slot by slot (each command should offer you the slot option).