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StarWind Virtual SAN®
Compute and Storage Separated 2-Node Scenario with VMware vSphere 6.5

Published: August 28, 2018


Traditionally, VMware requires having some sort of shared storage to guarantee the data safety, allow virtual machines migration, enable continuous application availability, and eliminate any single point of failure within IT environment. VMware users have to choose between two options when selecting the shared storage:

  • Hyperconverged solutions allow sharing the same hardware resources for the application (i.e. hypervisor, database) and the shared storage, thus decreasing the TCO and achieving the outstanding performance results.
  • Compute and Storage Separated solutions keep compute and storage layers separately from each other, thus making the maintenance easier, increasing the hardware usage efficiency, and allow building the system accurately for solving the task.

This guide is intended for experienced VMware and Windows system administrators and IT professionals who would like to configure StarWind Virtual SAN® Compute and Storage Separated solution for vSphere deployments. It provides a step-by-step guidance on how to configure a 2-node vSphere cluster with StarWind Virtual SAN® and connect StarWind nodes to the ESXi hosts to create fault-tolerant shared storage resource for ESXi.

A full set of up-to-date technical documentation can always be found here, or by pressing the Help button in the StarWind Management Console.

For any technical inquiries, please visit our online community, Frequently Asked Questions page, or use the support form to contact our technical support department.

Pre-Configuring Servers

The diagram below illustrates the network and storage configuration of the solution described in this guide.

the network and storage configuration of the solution

Preparing Hypervisor

Creating Datacenter

NOTE: Before creating Datacenter, the vCenter server should be deployed.

1. Connect to vCenter, select the Getting Started tab.

2. Click on Create Datacenter and enter Datacenter name.

Creating Cluster

3. Click the Getting Started tab in Datacenter, then click Create a cluster. Enter the name of the cluster and click Next.

Adding Hosts to Cluster

4. Open the Cluster pane and click Add a host.

5. Enter the Host name or IP address of the ESXi host and enter the administrative account.

6. Click Cluster -> Configure -> Edit. In vSphere Availability area, tick the Turn on vSphere HA checkbox.

Configuring Networks

Configure the network interfaces on each node to make sure that iSCSI interface is in different subnet and connected physically according to the network diagram above. In this document, one link with 10.30.1.x subnet per ESXi host is used for iSCSI traffic. All actions below should be applied to each ESXi server.

7. Create vSwitch for iSCSI traffic via the first Ethernet Switch.

NOTE: Virtual Machine Port Group and VMkernel should be created for iSCSI vSwitch. Static IP address should be assigned to VMkernel port.

NOTE: It is recommended to set jumbo frames to 9000 on vSwitches and VMkernel ports for iSCSI traffic. Additionally, vMotion can be enabled on VMkernel port.

8. Create a VMkernel port for iSCSI channel.

9. In VMkernel adapters pane, click Add host networking and Add Virtual Machine Port Group on the vSwitch for iSCSI traffic.

Preparing StarWind Servers

Install Windows Server 2016 (2012 R2) and StarWind VSAN on each host.

StarWind hosts should be with the following settings:

Make sure that server hardware used for StarWind Virtual SAN deployment satisfies the requirements listed below.

Minimum requirements:

RAM: 4 GB (plus the size of the RAM cache if applicable);
CPUs: 1 socket with 2 GHz;
Hard disk 1: 100 GB for OS (recommended);
Hard disk 2: Depends on the storage volume to be used as shared storage.

Network adapter 1: Management
Network adapter 2: iSCSI1
Network adapter 3: iSCSI2
Network adapter 4: Sync1
Network adapter 5: Sync2

It is recommended to set jumbo frames to 9000 for iSCSI and Synchronization traffic.

NOTE: Active Directory Domain Services role can be added on StarWind host if necessary, thus it can serve as a domain controller.

Downloading, Installing and Registering the Software

10. Download the StarWind setup executable file from our website by following the link:

11. Launch the downloaded setup file on the server where StarWind Virtual SAN will be installed. The setup wizard will appear.

12. Read and accept the License Agreement. Click Next to continue.

13. Read the information about new features and improvements. Red text indicates warnings for users who are updating existing software installations. Click Next to continue.

14. Select the following components for the minimum setup:

  • StarWind Virtual SAN Service

The StarWind service is the “core” of the software. It can create iSCSI targets as well as share virtual and physical devices. StarWind Management Console installed on any Windows computer or virtual machine in the network can manage the service. Alternatively, the service can be managed from StarWind Web Console deployed separately.

  • StarWind Management Console

The StarWind Management Console is the Graphic User Interface (GUI) part of the software that controls and monitors all storage-related operations (e.g. allows users to create targets and devices on StarWind Virtual SAN servers connected to the network).

15. Specify the Start Menu folder. Click Next to continue.

16. Enable the checkbox to create a desktop icon. Click Next to continue.

17. The appeared prompt will ask to request a time-limited fully functional evaluation key, or a FREE version key. Alternatively, the already purchased commercial license key for StarWind Virtual SAN can be used. Select the appropriate option.


18. Review the licensing information. Click Next to apply the license key.

19. Verify the installation settings. Click Back to make any changes or Install to continue.

20. Click Finish to complete the installation process. Optionally, StarWind Management Console can be launched by selecting the corresponding setting.

21. Repeat the steps above on the second host.

Provisioning Storage with StarWind VSAN

Creating StarWind HA devices

22. Open StarWind Management Console and click on the Add Device (advanced) button.

23. As Add Device Wizard appears, follow the instructions to complete creation of a new image device. Select Hard Disk Device as the type of a device to be created and click Next to continue.

24. Select the Virtual Disk option as a disk device type and click Next to continue.

25. Specify the virtual disk Name, Location and Size. Alternatively, use the existing virtual disk. Click Next to continue.

26. Select Thick-provisioned option. Click Next to continue.

NOTE: Sector size should be 512 bytes when using ESXi.

27. Define the RAM caching policy and specify the cache Size (in corresponding units). Click Next to continue.

NOTE: It is recommended to assign 1 GB of L1 cache in Write-Back or Write-Through mode per 1 TB of storage capacity. The cache size should correspond to the storage working set of the servers.

28. Define the Flash caching policy and the cache Size. Click Next to continue.

NOTE: The recommended size of the L2 cache is 10% of the initial StarWind device capacity.

29. Specify Target Parameters. Select the Target Name checkbox to enter a custom name of a target if required. Otherwise, the name will be generated automatically in accordance with the specified target alias. Tick the Allow multiple concurrent iSCSI connections checkbox to enable several clients to connect to the target simultaneously. Click Next to continue.

30. Click Create to add a new device and attach it to the target.

31. Click Finish to close the wizard.

32. Right-click on the recently created device and select Replication Manager from the shortcut menu.

33. Click Add replica.

34. Select Synchronous “Two-Way” Replication as a replication mode.

35. Specify a partner Host Name or IP address and Port Number. Click Next.

36. Select the appropriate Failover Strategy. Click Next.

NOTE: With Heartbeat failover strategy, one node remains active, even in case of all partner nodes failure.

With Node Majority failover strategy, the system can tolerate failure of only one node. If two nodes fail, the third one will become unavailable to clients’ requests.

This document describes the creation of an HA device with Heartbeat failover strategy.

The creation of an HA device with Node Majority failover strategy is covered in the following document:

C:\Users\yaprincev.dima\AppData\Local\Microsoft\Windows\INetCache\Content.Word\failover strategy.png

37. Select Create new Partner Device and click Next.

38. Select the device Location and specify a target name if required. Otherwise, the name is generated automatically in accordance with the specified target alias (recommended).

39. Click Change Network Settings.

40. Specify the interfaces for the Synchronization and Heartbeat channels.

41. Select Synchronize from existing Device. Click Next to continue.

42. Click Create Replica.

43. The successfully added devices appear in StarWind Management Console.

44. Repeat the steps above to create other virtual disks for use as datastores.

NOTE: For a 2-node StarWind cluster, it is recommended to create at least 2 HA devices.

Preparing Datastores

Adding Discover Portals

45. To connect the previously created devices to the ESXi host, log in to vCenter and click Storage -> Adapters -> Configure iSCSI. Select the Enabled option to enable Software iSCSI storage adapter.

46. In the Configure iSCSI window, under Dynamic Targets, click on the Add dynamic target button to specify iSCSI interfaces.

47. Enter the iSCSI IP address of both StarWind nodes from the local network. In this document, one link with 10.30.1.x and 10.30.3.x subnets per ESXi host is used for iSCSI traffic.

48. Rescan all storage adapters. In the Rescan Storage dialog, click OK

49. Now, the previously created StarWind devices are visible.

50. Repeat all the steps from this section on the other ESXi node, specifying the corresponding IP addresses for the iSCSI subnet.

Creating Datastores

51. Right-click on Datacenter ->Storage ->New Datastore.

52. Specify Datastore name, select the previously discovered StarWind device, and click Next.

53. Select the VMFS 6 file system. Click Next.

54. Enter Datastore Size. Click Next.

55. Verify the settings. Click Finish.

56. Add another Datastore in the same way but select the second device for the second datastore.

57. Verify that storages are connected to both hosts. Otherwise, rescan the storage adapter.

58. Path Selection Policy changing for Datastores from Most Recently Used (VMware) to Round Robin (VMware). For checking and changing this parameter manually, the hosts should be connected to vCenter.

59. Multipathing configuration can be checked only in vCenter. To check it, click the Configure button, select the Storage Devices tab, select the device, and click the Edit Multipathing button.

60. Select the Round Robin (VMware) MPIO policy.

Additional Tweaks

61. Select the ESXi host, open Configure tab, switch to Security Profile, and click Edit to configure Services.

62. Select SSH. Click the Start button and select Start and Stop with host as Startup Policy.

63. Connect to the host using the SSH client (e.g. Putty).

64. Check the device list using the following command:

65. For devices, adjust Round Robin size from 1000 to 1 using the following command:

NOTE: Paste UID of the StarWind device at the end of the command. Also, this parameter has been already added into the Rescan Script and this action is performed automatically.

66. Repeat the steps above on each host for each datastore.

67. Click the Configure tab on one of the hosts and select Advanced System Settings.

68. Select Disk and change the Disk.DiskMaxIOSize parameter to 512 and click OK.


This technical paper covers the configuration of the StarWind Virtual SAN for minimalistic Compute and Storage Separated scenario with VMware vSphere 6.5. In this setup, all virtual machines are stored within a shared storage provided by StarWind. VMware HA provides VMs with redundancy, while StarWind is responsible for the storage uptime. The combination of StarWind shared storage and VMware ensures high availability of applications and data across the entire virtualized environment. StarWind Virtual SAN provides data safety and maintains continuous application availability.