Читать книгу Mastering VMware vSphere 6 - Marshall Nick - Страница 24

As mentioned in the previous section, vSphere 6.0 vCenter Server comes not only as an installable Windows-based application but also as a SUSE Linux–based virtual appliance. As a result, a critical decision you must make as you prepare to deploy vCenter Server is which version you will use. Will you use the Windows Server–based version or the virtual appliance?

There are advantages and disadvantages to each approach:

• If your experience is primarily with Windows Server, you may not be familiar with the Linux underpinnings of the vCenter virtual appliance. This introduces a learning curve that you should consider.

• If you need support for Microsoft SQL Server, the Linux-based vCenter virtual appliance won’t work; you’ll have to deploy the Windows Server–based version of vCenter Server. However, if you are using Oracle, or if you are a small installation without a separate database server, the vCenter Server virtual appliance will work just fine (it has its own embedded Postgres database if you don’t need a separate database server).

• Conversely, if your experience is primarily with Linux or you manage a “Linux only by policy” datacenter, then deploying a Windows Server–based application will require some learning and acclimation for you and/or your staff.

• The Linux-based virtual appliance comes preloaded with additional services like Auto Deploy (covered in Chapter 2), Dynamic Host Configuration Protocol (DHCP), Trivial File Transfer Protocol (TFTP), and syslog. If you need these services on your network, you can provide them with a single deployment of the vCenter virtual appliance. With the Windows Server–based version, these services are separate installations or possibly even separate VMs (or, worse yet, separate physical servers!).

• Because the vCenter Server virtual appliance naturally runs only as a VM, you are constrained to that particular design decision. If you want to run vCenter Server on a physical system, you cannot use the vCenter Server virtual appliance.

As you can see, a number of considerations will affect your decision to deploy vCenter Server as a Windows Server–based installation or as a Linux-based virtual appliance.

My View on the vCenter Virtual Appliance

Some of the early support limitations around the SUSE Linux–based vCenter Server virtual appliance led people to believe that this solution was more appropriate for smaller installations. This may have been because the virtual appliance was certified to support only 5 hosts and 50 VMs or because deploying a virtual appliance that handles all the various services required would appeal more to a smaller implementation. However, VMware has now certified this solution to support up to 1,000 hosts and/or 10,000 VMs, so the former argument is no longer valid. The way I see it, you should always use the right tool for the job (with proper planning), and the vCenter Server virtual appliance is now the right tool for most vCenter jobs.

Something I like to point out when people have concerns with the virtual appliance is that VMware itself uses the vCenter Virtual Appliance internally for large-scale environments. A specific example is that of its Hands-on Labs. Even with this very large environment and intensive workloads, the virtual appliance is used.

In the next section, I’ll discuss some of the planning and design considerations that have to be addressed if you plan to deploy the Windows Server–based version of vCenter Server. Most of these issues apply to the Windows Server–based version of vCenter Server, but some may also apply to the virtual appliance; I’ll point those out where applicable.