vSphere 5.5 Virtual SAN requirements (2058424)
For more information, see the vSphere 5.5 documentation. The documentation contains definitive information. If there is a discrepancy between the documentation and this article, assume that the documentation is correct.
Virtual SAN requirements
Warning: Using uncertified hardware may lead to performance issues and/or data loss. The reason for this is that the behavior of uncertified hardware cannot be predicted. VMware cannot provide support for environments running on uncertified hardware.
- A minimum of three ESXi 5.5 hosts, all contributing local disks (1 SSD and 1 HDD).
- Each host must have a minimum of 6 GB of RAM.
- The host must be managed by vCenter Server 5.5 and configured
as a Virtual SAN cluster.
- Each host must have a minimum of a single physical 1 Gb Ethernet NIC available solely for Virtual SAN use.
- For more information on the Virtual SAN vSwitch configuration, see Configuring Virtual SAN VMkernel Networking (2058368).
- For best performance, use Jumbo Frames.
- Ensure Multicast is enabled. Multicast addresses can be changed if required.
- At least 1 SAS or SATA Solid State Drive (SSD).
- Ensure the SSD is not claimed by vSphere Flash Read Cache.
- Do not format SSDs with VMFS or any other file system.
- At least 1 SAS or SATA Hard Disk (HDD).
- A SAS or SATA Host Bus Adapter (HBA), or RAID controller that is set up in non-RAID (pass through) mode.
- Virtual SAN requires sole access to the host's local disks. Virtual SAN disks cannot be shared with another file system, such as Virtual Flash File System (VFFS), VMFS partitions, or an ESXi boot partition.
- If you install ESXi on a USB or SD device and allocate all
local storage to Virtual SAN, you do not have any local disk or
datastore available for persistent logging. Configure a Dump
Collector and a Syslog Collector to direct ESXi memory dumps and
system logs to a server on the network, rather than to a local
For more information, see:
- Introduction to vSphere Installation and Setup in the vSphere 5.5 Installation and Setup Guide.
- Configuring syslog on ESXi 5.x (2003322)
- ESXi Network Dump Collector in
VMware vSphere 5.x (1032051)
Virtual SAN cluster nodes with no local storageNot every host in the cluster needs storage. An ESXi host which is a Virtual SAN cluster node can start from SAN, SD/USB, or local disk. Virtual machines can then run in memory, reading virtual machine files from the local disks of other cluster nodes.
For example, consider this sample environment:
A 4-node Virtual SAN cluster named
Testgrouprunning 32 virtual machines. The Virtual SAN cluster nodes in
ESX1– Has 1 SSD and 1 HDD
ESX2– Has 1 SSD and 1 HDD
ESX3– Has 1 SSD and 1 HDD
ESX4– Has no local storage and is starting from SAN
- A Virtual SAN datastore is created from the available local storage
ESX3are used to create a 500 GB Virtual SAN datastore named
Note: SSDs do not contribute to the capacity of the Virtual SAN Datastore. SSDs are used only for read cache and write buffering.
Virtual machines stored on datastore
TestDSare available to all Virtual SAN cluster member hosts.
ESX4is running virtual machines stored on the
TestDSdatastore. The pieces of those virtual machines are physically located on storage which is locally attached to another cluster node. The virtual machine runs in the memory of host
ESX4, but the read and write data is sent across the Virtual SAN network to the local storage of the other nodes.
For more information on Virtual SAN requirements, see Requirements for Virtual SAN in the vSphere 5.5 Storage Guide.
Licensing for Virtual SAN
When you enable Virtual SAN on a cluster, you must assign the
cluster an appropriate Virtual SAN license before the 60-day
evaluation period expires.
License capacity and usage for Virtual SAN
Similar to vSphere licenses, Virtual SAN licenses have per CPU capacity. When you assign a Virtual SAN license to a cluster, the amount of license capacity that is used equals the total number of CPUs in the hosts that participate in the cluster. For example, if you have a Virtual SAN cluster that contains 4 hosts with 8 CPUs each, you need to assign the cluster a Virtual SAN license with a minimum capacity of 32 CPUs.
The license usage of the Virtual SAN cluster is recalculated and updated when:
- You assign a new license key to the Virtual SAN cluster
- You add a new host to the Virtual SAN cluster
- A host is removed from the cluster
- The total number of CPUs in a cluster changes
You must maintain the Virtual SAN clusters in compliance with the Virtual SAN licensing model. The total number of CPUs of all hosts in the cluster must not exceed the capacity of the Virtual SAN license that is assigned to the cluster.
All licensed editions of vSphere 5.5 are compatible with Virtual SAN. For more information, see the VMware Tribal Knowledge blog VMware Virtual SAN Now Available.
Virtual SAN for Desktop
Virtual SAN for Desktop is intended for use in VDI environments, such as vSphere for Desktop or VMware Horizon View. The license usage for Virtual SAN for Desktop equals the total number of powered on virtual machines in a cluster with enabled Virtual SAN.
To remain EULA compliant, the license usage for Virtual SAN for Desktop must not exceed the license capacity. The number of powered on desktop virtual machines in a Virtual SAN cluster must be less than or equal to the license capacity of Virtual SAN for Desktop.
License and evaluation period expiry
When the license or the evaluation period of a Virtual SAN expires, you can continue to use the currently configured Virtual SAN resources and features. However, you cannot add more hosts to the cluster or increase the SSD capacity on each host.
Assigning a license key to a Virtual SAN cluster
After you obtain an appropriate license key, assign it to your Virtual SAN cluster. Alternatively, you can use an existing Virtual SAN license key if one is available in the inventory of the vCenter Server system.
When you enable Virtual SAN for a cluster, you can use Virtual
SAN in evaluation mode to explore its features. The evaluation
period starts when Virtual SAN is enabled and expires after 60
days. To use Virtual SAN, you must license the cluster before the
evaluation period expires.
- Required privilege: Global.Licenses
- If you plan to assign an existing license, verify that the license key is available in the vCenter Server system.
- In the vSphere Web client, navigate to a cluster with enabled Virtual SAN.
- On the Manage tab, click Settings.
- Under Configuration, select Virtual SAN licensing and click Assign License Key.
- Select one of these licensing options:
- Assign an existing license key and then click OK.
- Assign a new license key using these steps:
- Type or copy and paste the license key and type an optional label for the key.
- To verify that the license key is in the correct format, and that it is for Virtual SAN, click Decode.
- Click OK.