Partition disks ('sdb') not being created on AKS regions running release v20250220

[stl327]

Upon creating AKS clusters using available SKUs on regions running the latest AKS release, further analysis shows that disk partitions (‘sdb’, namely are not getting created). This resulted in the same behavior (all repros are running ephemeral disks).

[stl327]

By default, in new create operations on supported k8s versions, if you have selected a VM SKU which supports Ephemeral OS disks but have not specified an OS disk size, AKS will provision an Ephemeral OS disk with a size that scales according to the total temp storage of the VM SKU, so long as the temp is at least 128GiB. If you are looking to utilize the temp storage of the VM SKU, you will need to specify the OS disk size during deployment, otherwise it will be consumed by default. See more information here: https://learn.microsoft.com/en-us/azure/aks/concepts-storage#default-os-disk-sizing

https://github.com/Azure/AKS/releases/tag/2025-02-20