For all you Sys Admins out there that manage vSphere you know how critical it is to have a reliable and easy to use management interface. VMware vCenter Server is the heart of a vSphere deployment, and provides a centralised platform for managing all the components of your vSphere deployment. These days vSphere administrators are presented with a number of supported deployment models for running vCenter Server, but there’s really only one that I prefer now, which is the vCenter Server Appliance. I know it wasn’t that flash in the early days, but it’s certainly matured. Read on for a little background and comparison.
What is the vCenter Server Appliance (vCSA)?
Historically, the deployment model for vCenter Server was to install the application on a Microsoft Windows server and host the vCenter Server Database (VCDB) in a supported database platform such as Microsoft SQL Server or Oracle Database.
As of vSphere 5.0, VMware have offered an alternative deployment model for the vCenter Server application, known as the vCenter Server Appliance (vCSA). In vSphere 6, the vCSA is a SUSE Linux virtual machine that gets deployed to an ESXi host or another vCenter Server, using a web based installer wizard, or alternatively it can be automated and deployed from the command line.
Throughout the vSphere 5.x versions, the vCSA lacked some of the features and scalability that could be achieved by installing vCenter on a Windows server. However, with the release of vSphere 6, VMware has put a lot of effort into bringing the vCSA up to scratch and it is now clearly the preferred deployment model in the eyes of VMware. Let’s spend a few minutes exploring the vCSA shipped with vSphere 6.
The vCSA is a SUSE Linux virtual machine, referred to as an appliance that is shipped by VMware and pre-loaded with all of the components required to run vCenter Server and/or the Platform Services Controller. The aim of the vCSA is to be entirely self-contained, resulting in decreased deployment and operational complexity. At the time of writing, VMware do support the use of an external Oracle database, but have announced deprecation for this particular deployment model, so it is not advised. The vCSA contains an embedded database (Postgres) that provides the same feature set and scalability as using an external database or a Windows install. The vCSA using the postgres database is the preferred deployment model as VMware have control over the operating system, vCenter application and the postgres database, meaning they can tune and tweak the appliance for given workloads and are able to design and enhance the product in a predictable manner – something which is much more difficult, if not impossible, with a traditional dispersed deployment.
Below is a feature comparison for vCenter Server deployed on Windows Server vs the vCSA, showing parity in terms of the scalability provided by each platform.
Benefits of vCSA over a traditional Windows installation
There are a number of benefits for deploying the vCSA and I've outlined some of the common ones below:
- Getting on board with the VMware preferred deployment model. The vCSA isn’t bleeding edge – it has been around for four major releases of vSphere and continues to receive focus and development from VMware.
- Faster deployment and upgrade times. This may not be relevant in many production scenarios, but for anyone doing regular lab/test/dev work with vCenter, this can be extremely beneficial.
- No Windows license(s) required, which could add up to a decent saving for organisations paying for a Windows Server operating system license per machine especially with multi-site deployments.
- Reduced patch management for the Windows operating system and database.
- Less overall complexity, including environment compatibility checks during updates and upgrades.
What are the drawbacks?
There are still a few "gotchas" to be aware of, but this list is getting progressively smaller with every release pushed out by VMware.
- At the time of writing, vSphere 6.0U2 is the latest release available, and vSphere Update Manager (VUM) still requires a separate installation of Microsoft Windows. This is the most common issue stopping vSphere administrators from moving to the current release of the vCSA, and VMware have made some public announcements to ‘watch this space’. I suspect we’ll see some movement on this at VMWorld 2016
- Currently there is no supported automated method to migrate from a Windows vCenter deployment directly to the vCSA. This is a topic that VMware have been very open about trying to fix and again, I suspect we’ll see some news about this at VMWorld 2016
- The vCSA is running on a Linux operating system, so depending on your skillset, Windows administrators without some basic Linux knowledge could find this to be a challenge
Can the vCSA replace my Windows vCenter?
At the end of the day, the answer to this is going to depending on each particular environment. With the vCSA shipped in vSphere 6, we’re finding it harder to come up with valid reasons to not use this as the preferred deployment method for vCenter Server and the Platform Services Controller.
As we watch and review the evolution of the vCSA, it is clear which direction VMware are heading with vCenter Server and how they want administrators to deploy vCenter to manage vSphere environments. At ViFX we have a number of customers running vCSA in their production environments and we expect to see even more uptake as VMware closes the gap and eliminates the remaining few weaknesses.
What are your thoughts on the vCenter Server Appliance? Are you already running it? Do you have anything holding you back from deploying vCSA? Let us know if the comments below.
Adam Eckerle is a Senior Technical Marketing Manager for vCenter at VMware and has written some blog posts on the VMware vSphere Blog titled ‘Getting comfortable with vPostgres and the vCenter Server Appliance’. Check out part 1 and part 2.