How to use Azure Elastic SAN as storage for Azure Kubernetes Service
There are two ways to use an Azure Elastic SAN as the backing storage for Azure Kubernetes Service (AKS). You can either use Azure Container Storage Preview, or use the open source Kubernetes iSCSI CSI driver.
Kubernetes iSCSI CSI driver
If you use the Kubernetes iSCSI CSI driver, you can connect an existing AKS cluster to Elastic SAN over iSCSI. Since you're manually managing this Elastic SAN, it can also be used for other workloads alongside AKS. However, if you use this configuration, Microsoft won't provide support for any issues stemming from the driver itself, since it's open source. Dynamic provisioning isn't currently supported with this configuration, and only ReadwriteOnce access mode is supported.
Azure Container Storage Preview
Azure Container Storage Preview is a cloud-based volume management, deployment, and orchestration service built natively for containers. For new or existing AKS clusters, you can install Azure Container Storage as an extension. After it's installed as an extension, you can programmatically manage and deploy storage, including Elastic SANs, through the Kubernetes control plane. In this case, Azure Container Storage deploys a SAN exclusively for use with your AKS cluster. That SAN can't be used for any other workloads and volume snapshots of that SAN's volumes isn't currently supported with this configuration.