Update VMSS instance mix docs with new examples and notes

Enhanced documentation for creating, updating, and viewing Virtual Machine Scale Sets (VMSS) with instance mix. Updated CLI examples to use newer VM sizes and added authentication parameters. Clarified that updating VM sizes replaces the entire list, not just individual sizes. Added common update scenarios for adding and removing VM sizes, and included example output for viewing the skuProfile.

Author: brittanyrowe

articles/virtual-machine-scale-sets/instance-mix-create.md

@@ -48,7 +48,9 @@ az vmss create \
   --resource-group {myResourceGroup} \
   --image ubuntu2204 \
   --vm-sku Mix \
-  --skuprofile-vmsizes Standard_DS1_v2 Standard_D2s_v4
+  --skuprofile-vmsizes Standard_D2s_v5 Standard_D2as_v5 \
+  --authentication-type ssh \
+  --generate-ssh-keys
 ```
 
 To specify the allocation strategy, use the `--skuprofile-allocation-strategy` parameter, like the following command:
@@ -58,8 +60,10 @@ az vmss create \
   --resource-group {myResourceGroup} \
   --image ubuntu2204 \
   --vm-sku Mix \
-  --skuprofile-vmsizes Standard_DS1_v2 Standard_D2s_v4 \
-  --skuprofile-allocation-strategy CapacityOptimized
+  --skuprofile-vmsizes Standard_D2s_v5 Standard_D2as_v5 \
+  --skuprofile-allocation-strategy CapacityOptimized \
+  --authentication-type ssh \
+  --generate-ssh-keys
 ```
 
 ### [Azure PowerShell](#tab/powershell-1)

articles/virtual-machine-scale-sets/instance-mix-update.md

@@ -37,6 +37,9 @@ az vmss update \
 #### Change the VM sizes
 To update the VM sizes in the `skuProfile`, for example, to Standard_D2as_v4, Standard_D2as_v5, and Standard_D2s_v5:
 
+> [!NOTE]
+> When you update VM sizes, you must specify the complete list of sizes you want in the scale set. This operation replaces the entire list, not just adds or removes individual sizes.
+
 ```azurecli-interactive
 az vmss update \
   --resource-group {resourceGroupName} \
@@ -155,7 +158,7 @@ az vmss update \
   --resource-group {resourceGroupName} \
   --set sku.name=Mix sku.tier=null \
   --skuprofile-vmsizes Standard_D2as_v4 Standard_D2s_v5 Standard_D2as_v5 \
-  --sku-allocat-strat capacityOptimized
+  --set skuProfile.allocationStrategy=capacityOptimized
 ```
 
 ### [REST API](#tab/arm-2)
@@ -188,5 +191,33 @@ In the request body, set `sku.name` to `"Mix"` and include the `skuProfile` with
 
 ---
 
+## Common update scenarios
+
+### Remove a specific VM size
+
+To remove a specific VM size from the instance mix configuration, specify the complete list of VM sizes you want to keep, excluding the size you want to remove.
+
+**Example**: Remove `Standard_D2as_v4` from a scale set that has `Standard_D2as_v4`, `Standard_D2s_v4`, `Standard_D2as_v5`, and `Standard_D2s_v5`:
+
+```azurecli-interactive
+az vmss update \
+  --resource-group {resourceGroupName} \
+  --name {scaleSetName} \
+  --skuprofile-vmsizes Standard_D2s_v4 Standard_D2as_v5 Standard_D2s_v5
+```
+
+### Add a specific VM size
+
+To add a new VM size to the instance mix configuration, specify the complete list of VM sizes including both existing and new sizes.
+
+**Example**: Add `Standard_D4s_v5` to a scale set that currently has `Standard_D2s_v4`, `Standard_D2as_v5`, and `Standard_D2s_v5`:
+
+```azurecli-interactive
+az vmss update \
+  --resource-group {resourceGroupName} \
+  --name {scaleSetName} \
+  --skuprofile-vmsizes Standard_D2s_v4 Standard_D2as_v5 Standard_D2s_v5 Standard_D4s_v5
+```
+
 ## Next steps
 Learn how to [troubleshoot](instance-mix-faq-troubleshooting.md) your instance mix-enabled scale set.

articles/virtual-machine-scale-sets/instance-mix-view.md

@@ -35,6 +35,21 @@ To display all properties in the `skuProfile`, run:
 az vmss show --resource-group <resourceGroupName> --name <scaleSetName> --query "skuProfile"
 ```
 
+**Example output:**
+```json
+{
+  "allocationStrategy": "CapacityOptimized",
+  "vmSizes": [
+    {
+      "name": "Standard_D4s_v5"
+    },
+    {
+      "name": "Standard_D4as_v5"
+    }
+  ]
+}
+```
+
 #### View VM sizes
 To display only the VM sizes, run:
 ```azurecli-interactive