I have AKS cluster and I would like to check a node disk type. I know there are 4 types of disk at the moment: standard HDD, standard SSD, premium SSD and ultra SSD (in preview). The node itself is set up to be Standard_DS2_v2 (via terraform) but there is no option (or I dont see it) for setting up certain disk type. How can I check disk type on Kubernetes node(s)?
Terraform, just like the Azure portal and az aks create, only allows you to select a predefined VM size.
Standard_DS2_v2 has "Premium SSD". All AKS nodes use SSD storage, in the provided link the ones with "Premium SSD" are listed as "Premium Storage: Supported".
Alternatively in the Azure Portal, create a new AKS resource (no need to really create it, just open the wizard), then in the first step, click the link "Change size" next to "Node size" and you'll get a list of available VM sizes with a column "Premium Disk Supported".
On an existing cluster, if you are using VMSS, you can also check the storage tier in the portal under the VMSS "Storage" tab, or by issuing az vmss list (storageProfile.osDisk.managedDisk.storageAccountType). Otherwise simply check the disk type in the virtual machine nodes AKS creates.
as far as I remember nodes are either standard or premium depending on the vm sku. if you are using a sku that supports premium disks it would use those. if you check AKS api reference for the agent pools, it has got no property for the disk type, so its being inferred for you.