11.3 vCenter Server High Availability Options
High availability of your vCenter Server and supporting services will depend on whether you have opted for a physical machine, Windows virtual machine, or the SUSE Linux-based appliance. Whichever platform has been chosen, protecting the vCenter Server and its supporting infrastructure is crucial for managing and monitoring hosts. Multiple options exist, so as with all design decisions, the service provider and consumer requirements dictate the design options available. Key answers that must be obtained regarding the availability of vCenter Server are:
• How much downtime can be tolerated?
• Should failover be a manual or automated process?
• What is the cost or impact of vCenter Server management service downtime?
For some environments, such as those using View or a service provider’s vCloud Director platform, where not even a minute or two of vCenter Server downtime can be tolerated, the architect is required to examine the options closely.
Table 29. vCenter Server Virtual Machine Availability Options
Availability Method | Windows vCenter Server | Windows Platform Services Controller Server | Windows vSphere Update Manager Server | Windows SQL Server | vCenter Server Appliance |
vSphere HA | Yes | Yes | Yes | Yes (risks DB corruption or non-consistent state) | Yes |
vSphere
SMP-FT | vSphere
SMP-FT | Supported only in specific user cases | Supported only in specific user cases | Yes | Yes |
Cold Standby VM and manual failover | Yes | No | Yes | No | Yes |
Microsoft failover clustering | No | No | No | Yes | No |
Third-party solutions | Yes | Yes | Yes | Yes | No |
Application integrated log shipping | N/A | N/A | N/A | Yes | No |
Active / passive load balanced configuration | No | Yes | No | No | No |
While cloning and manual failover is a viable option, it will typically take significantly longer to recover from than SMP-FT or vSphere HA. vCenter Server is essentially stateless. However, with this manual approach, it takes time to not only create the initial cold clone, but also to keep the redundant server up-to-date. It is also possible to keep a cold standby virtual machine of a physical vCenter Server by using physical-to-virtual conversion software to create the clone.