Nexus 55xx NX-OS upgrades without interruption

[Brian Meston]

Is it possible to upgrade Nexus 5548 and 5596 switches from 5.2 to 7.1, without interruption to the downstream devices?

We have numerous pairs of Nexus 55xx switches in remote data centers. We need to upgrade the NX-OS to 7.x in order to fix some security issues. We are looking for a path to ISSU upgrade them even if it means multiple upgrades from 5.2 to 6.02 to 7.0 to 7.1, or whatever. We cannot afford downtime to the servers and storage arrays behind them.

Unfortunately, we found that upgrading from 6.02 to 7.1 was impactive. For some reason, the upgrade shut down our mgmt0 interface, which carries our vpc keep-alives. It also wiped out the port-configs on all the associated FEX ports. We had to console into the switches and 'no shut' the mgmt0 interface and rebuild all the FEX port configs. 

Any advice would be much appreciated.

-Brian

[Leo Laohoo]

Is it possible to upgrade Nexus 5548 and 5596 switches from 5.2 to 7.1, without interruption to the downstream devices?

Depends on the setup.

When you upgrade the firmware of the switch, you have to reboot the switch.  If your downstream device is only connected to a single physical switch unit (Catalyst or Nexus) then there's really no chance of a "no outage".  If you're downstream device is connected via a dual NIC and each leg is a different physical switch, then it's possible but you'll get a small amount of ping drops.  

There are a lot of factors involved.  There is also a possibility that the server NIC cards may NOT be configured properly.  

Have I done something like this?  Yes, but not to a Nexus (no-go-zone for me).  On a Catalyst switch, it is very much possible with stacking and/or VSS combination.  But the server configuration also has something to play too.

[alessandro.s]

Hi Brian,

as Leo said, it depends on your setup but keep in mind that ISSU is not possible if you have L3 modules installed in you N5K switches. I suggest you to follow this guide :

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/upgrade/710_N1_1a/n5500_upgrade_downgrade_710.html#pgfId-641779

it contains very useful step-by-step guidelines to upgrade N5K switches in different environments.

If you have a service contract for N5K switches you can also open a TAC about the upgrade,  they will provide you all the informations you need like  upgrade steps to follow, requirements and so on. I'm going to upgrade a pair of N5K switches Tomorrow evening and Cisco also provided me  a direct contact to call in case of Emergency during upgrade operations.

Best Regards,

Alessandro