Ever since it was first released with vSphere 5.0, the vCenter Server Appliance (vCSA) has been an intriguing proposition for VMware administrators. The installation process for the appliance is much simpler than the Windows-based install, and there are significant cost savings from jettisoning Windows and SQL license requirements. However, the relative 'newness' and some support limitations on max ESXi / VM counts, as well as features missing, have made many users wary of it, especially in production.
In the 5.5 release, vCSA extends local database support from a mere 5 ESXi hosts and 50 VMs up to 100 ESXi hosts and 3,000 VMs. (Connecting it to an external Oracle database, however, extends these maximums to 1,000 ESXi hosts, and 10,000 VMs.)
So, infrastructure size is no longer a problem for most environments, even if an external database is not an option. What, then, are the major differences you need to know about with the vCSA when considering implementing it?
The vCSA is a virtual appliance, that runs the vCenter Server application in a 64-bit SuSE 11 environment. As such, most of the vCSA 5.5 limitations are primarily based on services that rely on Windows, or Windows components. It is likely that these components will be included in future releases of the vCSA.
Still, in order to properly evaluate the product's fit in any environment, it's important to understand these limitations. Here are the main missing features of the vCSA, and the reasons behind their absence:
Update Manager is another Windows application, which cannot be installed in Linux. You can still get it up and running on a separate Windows VM.
vCenter Linked Mode
Linked mode relies on Microsoft's Active Directory Application Mode (ADAM) user service, which is not available in Linux.
vCenter Heartbeat is a Windows application that only installs on Windows Server 2008/2012, and only protects SQL Server databases.
Security Support Provider Interface (SSPI)
SSPI is a part of SSO. It is a Microsoft based Windows API used to authenticate against Security Support Providers, such as NTLM or Kerberos.
There are only two options for database connections to the vCSA:
- The built-in vPostgres (up to 100 hosts and 3,000 VMs)
- An external Oracle Database (up to 1,000 hosts and 10,000 VMs)
VMware/Third Party Applications
Some additional components that previously were installed on the vCenter Server will need to be installed on a separate Windows machine. An example is the NetApp Virtual Storage Console. Consult with third party vendors for details on supported installation configurations.
VMWare's (concise) statement on this issue:
- vCSA does not support IPv6.
All told, the vCSA is much easier to install and keep updated than its Windows counterpart. Additionally, its functionality continues to get more streamlined with each release, with large numbers of bug fixes in 5.50a, 5.50b, and the latest 5.5u1.
Overall, the product has made enormous strides forward since it's initial release and should warrant full consideration for installation in any new or existing VMware environment.
Labels: vCenter, vCSA, Vmware, vSphere, vSphere 5.x