What is vCenter Server Appliance?

Two options are available for installing vCenter Server:

  • Windows-based installation
  • vCenter Server Appliance deployment

Both options provide features such as inventory management, virtual machine migration, high availability, distributed resource scheduling, etc. Both options offer the identical user experience. In fact, users connecting to vCenter Server will not even know on which platform vCenter Server is installed on.

vCenter Server Appliance is a preconfigured SUSE Linux-based virtual machine optimized for running vCenter Server and the associated services. It is a prepackaged 64-bit application with an embedded PostgreSQL database that supports up to 100 hosts and 3000 virtual machines.

vCenter Server Appliance comes as an Open Virtualization Format (OVF) template. The appliance is imported to an ESXi host and configured through the web-based interface. It comes pre-installed with all the components needed to run a vCenter Server, including vCenter SSO (Single Sign-on), Inventory Service, vSphere Web Client and the vCenter Server itself.

Here are the main benefits of using the vCenter Server Appliance over the vCenter Server Windows installation:

  • simplified deployment. The appliance is simply imported to an ESXi host.
  • simplified configuration. The web-based interface is used for configuration.
  • lower cost of ownership, since no Windows OS license is required.
  • embedded database supports larger environments than embedded database on vCenter Server installed on Windows.

The vCenter Server Appliance can be downloaded from the vCenter Server 5.x download page.

Here are the system requirements for vCenter Server 5.5 Appliance:

Disk storage on the host machine:

vCenter Server Appliance 5.0.x / 5.1.x:

  • At least 7 GB
  • A maximum of 80 GB

vCenter Server Appliance 5.5.x:

  • At least 70 GB
  • A maximum of 125 GB

Memory in the vCenter Server Appliance:

vCenter Server Appliance 5.5.x:

  • Very small inventory (10 or fewer hosts, 100 or fewer virtual machines) – at least 8 GB.
  • Small inventory (10-50 hosts or 100-1500 virtual machines) – at least 16 GB.
  • Medium inventory (the maximum inventory supported with the embedded database; 50-100 hosts or 1500-3000 virtual machines) – at least 24 GB.
  • Large inventory (More than 400 hosts or 4000 virtual machines) – at least 32 GB.


  • two virtual CPUs.

The vCenter Server Appliance must also have the JVM heap settings configured. Here are the recommended values:

vCenter Server Appliance hardware


Query Service (QS)

Policy Based Storage Management (SPS)

Small inventory (1-100 hosts or 1-1000 virtual machines)

512 MB

3 GB

1 GB

Medium inventory (100-400 hosts or 1000-4000 virtual machines)

512 MB

6 GB

2 GB

Large inventory (more than 400 hosts or 4000 virtual machines)

1 GB

12 GB

4 GB

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