Merge pull request #298895 from roygara/avesanRefresh

Elastic San VMware Solution refresh

Author: denrea

articles/azure-vmware/configure-azure-elastic-san.md

@@ -21,64 +21,65 @@ To accompany the steps below, you can use this [interactive demo](https://regale
 
 The following prerequisites are required to continue.
 
-- Verify you have a private cloud in a [region that Elastic SAN is available in](../storage/elastic-san/elastic-san-create.md).
+- Have a fully configured Azure VMware solution private cloud in a [region that Elastic SAN is available in](../storage/elastic-san/elastic-san-create.md).
+    - Size your ExpressRoute gateways to handle your elastic SAN's bandwidth capabilities. For example, a single ultra performance ExpressRoute gateway supports a bandwidth of 1,280 mbps. An individual elastic SAN datastore used to its full potential would use the entirety of that bandwidth. Multiple gateways might be required depending on your needs.
 - Know the availability zone your private cloud is in. 
   - In the UI, select an Azure VMware Solution host.
     > [!NOTE]
-    > The host exposes its Availability Zone. You should use that AZ when deploying other Azure resources for the same subscription.
-    
-- You have permission to set up new resources in the subscription your private cloud is in.
+    > The host exposes its availability zone. Use that availability zone when deploying other Azure resources for the same subscription.
 
+- Have permission to set up new resources in the subscription your private cloud is in.
 - Reserve a dedicated address block for your external storage.
+- Use either the [Azure portal](/azure/storage/elastic-san/elastic-san-create?tabs=azure-portal), [Azure PowerShell module](/azure/storage/elastic-san/elastic-san-create?tabs=azure-powershell), or [Azure CLI](/azure/storage/elastic-san/elastic-san-create?tabs=azure-cli) to create an Elastic SAN that has at least 16 TiB base size and that is in the same region and availability zone as your private cloud.
+    > [!NOTE]
+    > Make sure CRC protection on your volume groups is disabled since it's not currently supported for Azure VMware Solution.
+
 
 ## Supported host types
 
-To use Elastic SAN with Azure VMware Solution, you can use any of these host types:
+You can use the following host types when Azure Elastic SAN is the backing storage for Azure VMware solution:
 
-- AV36 
+- AV36
+- AV36P
+- AV52
+- AV64
 
-- AV36P 
+## Configuration recommendations
 
-- AV52 
+Use multiple private endpoints to establish multiple sessions between an Elastic SAN and each volume you intend to connect to your software defined data center (SDDC). Having multiple sessions provides better performance due to parallelization, and better reliability to handle single session disconnects. When you establish multiple sessions, it also mitigates the impact of session disconnects, as long as the connection is re-established within a few seconds, your other sessions help load-balance traffic.
 
-- AV64
+   > [!NOTE]
+   > Session disconnects might show up as "All Paths Down" or "APD" events, which can be seen in the Events section of the ESXi Host at vCenter. You can also see them in the logs: it shows the identifier of a device or filesystem, and states it entered the All Paths Down state.
 
-- AV48
-
-## Set up Elastic SAN
-
-In this section, you create a virtual network for your Elastic SAN. Then you create the Elastic SAN that includes creating at least one volume group and one volume that becomes your VMFS datastore. Next, you set up private endpoints for your Elastic SAN that allows your private cloud to connect to the Elastic SAN volume. Then you're ready to add an Elastic SAN volume as a datastore in your private cloud.
-
-1. Use one of the following instruction options to set up a dedicated virtual network for your Elastic SAN:
-	- [Azure portal](../virtual-network/quick-create-portal.md)
-	- [Azure PowerShell module](../virtual-network/quick-create-powershell.md)
-	- [Azure CLI](../virtual-network/quick-create-cli.md)
-1. Use one of the following instruction options to set up an Elastic SAN, your dedicated volume group, and initial volume in that group:
-      > [!IMPORTANT]
-   > 
-   > Create your Elastic SAN in the same region and availability zone as your private cloud for best performance.
-   - [Azure portal](/azure/storage/elastic-san/elastic-san-create?tabs=azure-portal)
-   - [PowerShell](/azure/storage/elastic-san/elastic-san-create?tabs=azure-powershell)
-   - [Azure CLI](/azure/storage/elastic-san/elastic-san-create?tabs=azure-cli)
-1. Use one of the following instructions to configure a Private Endpoint (PE) for your Elastic SAN:
-      > [!IMPORTANT]
-   > 
-   > You must have a Private Endpoint set up for your dedicated volume group to be able to connect your SDDC to the Elastic SAN.
-   - [Azure Portal](/azure/storage/elastic-san/elastic-san-networking?tabs=azure-portal#tabpanel_2_azure-portal)
-   - [PowerShell](/azure/storage/elastic-san/elastic-san-networking?tabs=azure-powershell#configure-a-private-endpoint)
-   - [Azure CLI](/azure/storage/elastic-san/elastic-san-networking?tabs=azure-cli#tabpanel_2_azure-cli)
+When an Elastic SAN volume is attached to a cluster, it automatically attaches to all nodes. If you have 16 nodes and each node is configured to use eight iSCSI sessions that use the maximum number of connections (128). This would prevent you from attaching an additional node for maintenance. The following recommendations help you avoid this situation:
 
-## Configuration recommendations
+If your Elastic SAN is only connecting to a single cluster, and will only ever have 16 nodes in a cluster, use one of the following configurations:
+- AV36, AV36P, AV52 - Six iSCSI sessions over three Private Endpoints
+- AV64 - Seven iSCSI sessions over seven Private Endpoints
 
-You should use multiple private endpoints to establish multiple sessions between an Elastic SAN and each volume group you intend to connect to your SDDC. Because of how Elastic SAN handles sessions, having multiple sessions comes with two benefits: increased performance thanks to parallelization, and increased reliability to handle single session disconnects due to unexpected factors like network glitches. When you establish multiple sessions, it mitigates the impact of session disconnects, as long as the connection re-established within a few seconds, your other sessions help load-balance traffic.
+If your Elastic SAN is connecting to a single cluster that won't have 16 nodes, use one of the following configurations.
+-  AV36, AV36P, AV52 - Eight iSCSI sessions over four Private Endpoints
+- AV64 - Eight iSCSI sessions over eight Private Endpoints
 
-   > [!NOTE]
-   > Session disconnects may still show up as "All Paths Down" or "APD" events, which can be seen in the Events section of the ESXi Host at vCenter. You can also see them in the logs: it will show the identifier of a device or filesystem, and state it has entered the All Paths Down state.
+If you're planning on connecting an Elastic SAN datastore to multiple clusters, you must calculate the number of hosts, sessions, and connections per cluster. An Elastic SAN datastore only supports a maximum of 128 connections, and each time you connect an Elastic SAN datastore to a cluster, it automatically connects to all nodes in that cluster. This can rapidly use up the available connections when each node in a cluster is establishing multiple connections.
+
+## Configure Private Endpoint
+
+Using the guidance from the previous section, create as many private endpoints for your volume groups as you need.
+
+Edit your volume group, or create a new one. Then select **Networking**, then select **+ Create a private endpoint** under **Private endpoint connections**. You don't need to configure a dedicated virtual network for your Elastic SAN, since you're using private endpoint connections to access your Elastic SAN volumes.
+
+Fill out the values in the menu that pops up, select the virtual network that has your [ExpressRoute connection configured](/azure/azure-vmware/tutorial-configure-networking#connect-expressroute-to-the-virtual-network-gateway), and the subnet that your applications are going to use to connect. When you're done, select **Add**, and **Save**.
+
+ Repeat these steps to create as many private endpoints as you need.
+
+:::image type="content" source="../storage/elastic-san/media/elastic-san-create/elastic-san-edit-volume-network.png" alt-text="Screenshot of the volume group private endpoint creation experience." lightbox="../storage/elastic-san/media/elastic-san-create/elastic-san-edit-volume-network.png":::
+
+> [!NOTE]
+> Using Private Endpoints provides the highest network security. However, since your private cloud connects to Elastic SAN in Azure through an ExpressRoute virtual network gateway, you might experience intermittent connectivity issues during [gateway maintenance](/azure/expressroute/expressroute-about-virtual-network-gateways). 
+> These connectivity issues aren't expected to impact the availability of the datastore backed by Elastic SAN as the connection is re-established within seconds. The potential impact from gateway maintenance is covered under the [Service Level Agreement](https://www.microsoft.com/licensing/docs/view/Service-Level-Agreements-SLA-for-Online-Services?lang=1) for ExpressRoute virtual network gateways and private endpoints.
 
-Each private endpoint provides two sessions to Elastic SAN per host. The recommended number of sessions to Elastic SAN per host is 8, but because the maximum number of sessions an Elastic SAN datastore can handle is 128, the ideal number for your setup depends on the number of hosts in your private cloud. 
 
-   > [!IMPORTANT]
-   > You should configure all Private Endpoints before attaching a volume as a datastore. Adding Private Endpoints after a volume is attached as a datastore will require detaching the datastore and reconnecting it to the cluster.
 ## Configure external storage address block
 
 Start by providing an IP block for deploying external storage. Navigate to the **Storage** tab in your Azure VMware Solution private cloud in the Azure portal. The address block should be a /24 network. 
@@ -88,34 +89,30 @@ Start by providing an IP block for deploying external storage. Navigate to the *
 - The address block must be unique and not overlap with the /22 used to create your Azure VMware Solution private cloud or any other connected Azure virtual networks or on-premises network. 
 - The address block must fall within the following allowed network blocks: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. If you want to use a non-RFC 1918 address block, submit a support request. 
 - The address block can't overlap any of the following restricted network blocks: 100.72.0.0/15 
-- The address block provided is used to enable multipathing from the ESXi hosts to the target, it can’t be edited or changed. If you do need to change it, submit a support request. 
-
-## Connect Elastic SAN
+- The address block provided is used to enable multipathing from the ESXi hosts to the target, it can’t be edited or changed. If you do need to change it, submit a support request.
 
-After you provide an External storage address block, you need to connect your private cloud express route with the private endpoint(s) you set up for your Elastic SAN volume group(s). To learn how to establish these connections, see [Configure networking for your VMware private cloud in Azure](../azure-vmware/tutorial-configure-networking.md). 
-
-> [!NOTE]
-> Connection to Elastic SAN from Azure VMware Solution happens via private endpoints to provide the highest network security. Since your private cloud connects to Elastic SAN in Azure through an ExpressRoute virtual network gateway, you may experience intermittent connectivity issues during [gateway maintenance](/azure/expressroute/expressroute-about-virtual-network-gateways). 
-> These connectivity issues aren't expected to impact the availability of the datastore backed by Elastic SAN as the connection will be re-established within seconds. The potential impact from gateway maintenance is covered under the [Service Level Agreement](https://www.microsoft.com/licensing/docs/view/Service-Level-Agreements-SLA-for-Online-Services?lang=1) for ExpressRoute virtual network gateways and private endpoints.
 ## Add an Elastic SAN volume as a datastore
 
+Configure all Private Endpoints before attaching a volume as a datastore. Adding Private Endpoints after a volume is attached as a datastore requires detaching the datastore and reconnecting it to the cluster.
+
 Once your SDDC express route is connected with the private endpoint for your Elastic SAN volume group, use the following steps to connect the volume to your SDDC: 
 
 1. From the left navigation in your Azure VMware Solution private cloud, select **Storage**, then **+ Connect Elastic SAN**.
 1. Select your **Subscription**, **Resource**, **Volume Group**, **Volume(s)**, and **Client cluster**.
 1. From section, "Rename datastore as per VMware requirements", under **Volume name** > **Data store name**, give names to the Elastic SAN volumes.
-      > [!NOTE]
-   > For best performance, verify that your Elastic SAN volume and private cloud are in the same Region and Availability Zone.
+   > [!NOTE]
+   > When creating virtual disks, use eager zeroed thick provisioning.
+   > This means setting up virtual disks where all the space is reserved and cleaned out in advance, so they're ready for fast and secure use.
 
 ## Disconnect and delete an Elastic SAN-based datastore
 
 To delete the Elastic SAN-based datastore, use the following steps from the Azure portal.
 
 1. From the left navigation in your Azure VMware Solution private cloud, select **Storage**, then **Datastore list**.
-1. On the far right is an **ellipsis**. Select **Delete** to disconnect the datastore from the Cluster(s).
+1. On the far right is an **ellipsis**. Select **Delete** to disconnect the datastore from the clusters.
 
    :::image type="content" source="media/configure-azure-elastic-san/elastic-san-datastore-list-ellipsis-removal.png" alt-text="Screenshot showing Elastic SAN volume removal." border="false"lightbox="media/configure-azure-elastic-san/elastic-san-datastore-list-ellipsis-removal.png":::
 
-1. Optionally you can delete the volume you previously created in your Elastic SAN.
+1. Optionally, you can delete the volume you previously created in your Elastic SAN.
       > [!NOTE]
    > This operation can't be completed if virtual machines or virtual disks reside on an Elastic SAN VMFS Datastore.