Hello Everyone!
It’s been a while since I wrote my last post. Many many things happened both in my life as well as work. Not an excuse for my lack of posting, but I do plan to get back to blogging more consistently in the year 2023.
What do we have here today?
In today’s edition, I bring you I script I wrote to move T1 gateways across Edge Clusters in NSX-T. It can programmatically move hundreds of T1s in a couple minutes.
LINK TO THE SCRIPT
Why would I need to move my T1 Gateways across Edge Clusters?
There are multiple scenarios that would trigger the need to move / evacuate T1 gateways to a different Edge Cluster. The most common are:
- During a NSX-V to NSX-T migration, Migration Coordinator will, by default, put all T1 gateways in the same Edge Cluster that is being used for the T0s. In an architecture where there is a dedicated Edge Cluster for T0 ECMP / Uplink, and Edge Cluster/s used for T1 Stateful services (such as load balancing) this is not ideal.
- A 10-node XL Edge Cluster can only host up to 400 Small load balancers. Going over this limit will require to build an additional Edge Cluster. vRA can only deploy Load Balancers to a single Edge Cluster at any given time per any given Network Profile. If we reach the limit, we either create the new cluster and change the network profile to the new cluster, or, we can migrate the current T1s to the new cluster, and keep using the one we previously had in the network profile
- Rebalancing of T1 Gateways across Edge Cluster for maintain a similar number of T1s across all edge clusters.
How do I use this script?
In the initial comments of the script there is an explanation of the usage
<################################################
Move (T1s) across edge clusters
Author: @ldelorenzi - Jan 23
Usage:
moveT1s.ps1 -nsxUrl <NSX Manager URL (with HTTPS)) -sourceClusterName <Edge Cluster Name> -destinationClusterName <Edge Cluster Name> -execute <$true/$false> -count <count of load balancers to move>
Credentials will be asked at the beginning of the run
################################################>
To dive a little bit deeper into these parameters:
- nsxUrl: The NSX-T manager we will be hitting with this script. Including HTTPS
- sourceClusterName: The name of the Edge Cluster that hosts the T1 Gateways we want to move
- destinationClusterName: The name of the Edge Cluster that will receive the T1 Gateways from the source cluster
- execute: By default, the execute flag is set to false. This means that if no value is used in the script, it will default to false. If execute is false, the script will only show us what T1s were found in the source cluster and therefore will be moved to the destination cluster
- count: If you don’t want to fully evacuate the cluster and you want to just move some T1s from source cluster to destination cluster, you can set a value for the count parameter and that will limit the amount of T1s that are moved.
Interesting things about the Script
- If you look at the code you will see that I built my own wrapper for invoke-RestMethod called restCall – this function has logging included as well as retries. If you’re going to have a lot of REST API calls in your scripts, it could make sense to include something like this!
- The ‘movement’ of T1 Gateways actually involves patching the T1 SR object with its new cluster ID. The script finds the Edge Cluster IDs using the names provided at the beginning of the run. This makes it friendlier for users / admins since just the name can be used instead of having to find the id.
Closing Note
I hope you enjoy this post and make use of this script in your environments. If you liked this, please share it!
Until next time!
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