Azure Virtual Machine Scale Set (VMSS) Part1 — Architecture and Deployment

  • Easy to create and manage multiple VMs
  • Provides high availability and application resiliency
  • Allows your application to automatically scale as resource demand changes
  • Works at large-scale


Image Source: Virtual Machine Scale Set (VMSS) — MyKloud (


Network Management

az network lb inbound-nat-pool show -g MyResourceGroup --lb-name MyLb -n MyNatPool
az vmss list-instance-connection-info \
--resource-group myResourceGroup \
--name myScaleSet
ssh jonw@ -p 50000
az vmss extension set \
--publisher Microsoft.Azure.Extensions \
--version 2.0 \
--name CustomScript \
--resource-group <resource group name> \
--vmss-name <scale set name> \
--settings '{"fileUris":[""],"commandToExecute":"./"}'
# SSH into one of the instances
- ssh <username>@<VMSS public IP> -p <LB frontend assigned port>
# examine partitions
- sudo fdisk -l
# examine filesystems and mount points
- sudo df -h
  • Reimage: This means the instance within VMSS will be deleted and replaced by an instance created from the original assigned image.
  • Update: This is used when there is no upgrade policy.
  • Upgrade: This is used changes made on the scale set need to be applied to each instance. There are 3 different policies, automatic, manual and rolling.



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Learning new things about Kubernetes every day. Hopefully, the learning notes could help people on the same journey!