Description

HCI supports multi-volume management. Normal volumes and stretched volumes can exist on a cluster at the same time. Multiple virtual datastore can be created in the HCI cluster, and volumes are physically and logically isolated. But for virtual machines, volumes can be selected and migrated, and they can also meet the heterogeneous hardware requirements of different services in the cluster. The following operations are for adding stretched volumes.

Precautions

1. The newly added volume will be formatted when it is created. Before adding, please make sure that there is no data that needs to be preserved on the disk used to add the new volume.

2. HCI builds volumes based on the host as the basic unit. Please plan ahead to create a cluster.
3. The deployment mode of the witness node supports physical machine deployment and VMware virtualization deployment. Using the management interface to communicate with the data node is recommended.

Prerequisites

1. A stretched cluster starts with at least four hosts plus one witness node. In actual deployment, it is necessary to ensure that the node location configured on the page is consistent with the actual physical location. Otherwise, protection at the computer room level cannot be achieved. The two fault domain computer rooms must be connected at Layer 2, and the link of the witness node does not need to be connected at Layer 2, but make sure it is reachable by the network.

Steps

1. Configure the volume type and the number of data copies: Navigate to Storage > Virtual Storage > Virtual Datastores, click New, and select the volume Type as Stretched datastore.

2. Select Node: Select the host that needs to be added to the stretched datastore. The stretched datastore requires at least four hosts and set the two hosts in different fault domains.

3. Specify Fault Domain: Add the required hosts to the corresponding fault domain. In this example, there are four hosts, so two hosts are added to the primary fault domain and two hosts are added to the secondary fault domain.

4. Add witness node: After configuring the main computer room and the standby computer room, configure the witness node IP according to the pre-installed witness node. Follow the wizard to enter the password to confirm the configuration of the witness node, and then confirm the configuration.

5. Verify the configuration: Confirm the configuration of the fault domain. After completion, it is not possible to modify the fault domain.

6. Configure use of disk: Each node must have a cache disk and data disk.  Note: Stretched virtual datastore has to configure witness node witness disk. Each witness disk requires at least 100GB.

7. Confirm the configuration: The configuration information of the virtual storage is displayed here, including the final storage capacity, the number of copies, and the number of disks. After confirming that the configuration is correct, you need to enter the administrator password and click Finish to initialize the virtual storage.