In-Depth
The Essential VMware
To get your virtualization project off the ground, all you need to know about VMware are its core products. Here's an overview.
If you're considering virtualizing some of the servers in your organization and want to use VMware, sooner or later you're going to have to figure out what components you want to include in your architecture. This can be a daunting challenge for anyone, even those experienced with VMware. VMware offers a number of products related to server virtualization, and many of them have cryptic names such as ESXi or vCenter Site Recovery Manager (SRM). Here, I'll cut through the confusing and evolving list of products and solutions by explaining what some of the VMware products do, how they fit into your infrastructure, and which ones you really need to get your cloud or virtualization projects started.
Putting It into Perspective
If you haven't yet delved into the world of VMware, you might be wondering how complicated the technology could possibly be. After all, VMware has become the de facto hypervisor for countless organizations.
To put things into perspective, consider Hyper-V, the Microsoft hypervisor. Hyper-V comes with the Windows Server OS, or there's a standalone version you can download. Hyper-V includes everything you need to create, run and manage VMs. If you need additional management capabilities (which are nearly essential in large-scale deployments), Microsoft offers a management tool called System Center Virtual Machine Manager (VMM).
The reason I point this out is that Microsoft -- which is one of VMware's primary competitors -- has a server virtualization solution that's based primarily around the use of two products. In contrast, if you go to the VMware Products page (at vmware.com/products), you'll see VMware offers about 40 products. Obviously, I can't cover all of these products within the confines of a single article, but I will talk about the essential ones.
The Core Hypervisor
The first component you're going to need is a core hypervisor. The VMware hypervisor is known as VMware vSphere ESXi. Previously, VMware offered a hypervisor known as ESX, but ESX is now considered to be a legacy product.
One thing that really differentiates vSphere from Hyper-V is that it's much lighter-weight. In fact, ESXi version 5.1 has a disk footprint that's only about 150MB in size. Needless to say, VMware really kept the hypervisor's feature set to a minimum in order to make it so lightweight.
Because ESXi is so lightweight, you can't use the server console to create and manage VMs as you can with Hyper-V. Instead, you need a client. VMware calls its fat client VMware vSphere. The vSphere Client can't be installed onto a vSphere server. It's intended for installation on a PC. You can download the vSphere Client from a vCenter Server (which I'll talk about later) or you can get it off of the vCenter installation media.
vCenter Server
The most essential component beyond the vSphere hypervisor is arguably vCenter Server. vCenter Server is a management tool you can use to manage all of your vSphere servers and their virtualized workloads through a single pane of glass. In some ways, vCenter Server is comparable to Microsoft VMM.
vCenter Server provides visibility into your virtualization infrastructure through something called the Inventory Service. This service makes it possible to see hosts, VMs, virtual networks and data stores that exist throughout your organization.
Another useful service provided by vCenter is single sign-on (SSO). vCenter SSO makes it possible to log in once and access the entire vCenter environment. This is especially helpful in extremely large deployments (and VMware environments can grow to be quite large), as it's possible to accommodate 30,000 VMs by linking together 10 vCenter instances.
As I explained, the vSphere Client is normally used for managing the VMs that exist on a vSphere server. vCenter includes a Web client that allows you to manage your virtual datacenter through a Web browser.
Incidentally, if you plan to use the vCenter Web Client, the SSO service must be enabled and the vSphere Web client and the vCenter Server must be registered to a common vCenter SSO server. The Inventory Service is also required in order for the vCenter Web client to work.
vCenter can also be used to monitor your physical hardware. Not only can the software alert you to things like server failures, but it can alert you to less-extreme problems before they turn into bigger problems. For instance, it's possible to use vCenter hardware monitoring to detect and report server fan failures. Doing so allows you to take corrective action before other, more expensive server components begin to fail as a result of overheating.
Another major function of vCenter Server is securing the virtualization infrastructure. Once upon a time, administrators had access to all IT resources across the entire organization. Today this is no longer the case in most midsize and large organizations. Administrative responsibilities are separated in a way that prevents any one single administrator from having total control. vCenter Server allows for the creation of various administrative roles, and can assign fine-grained permissions to each role based on the role's responsibilities. It's also worth noting that vCenter Server provides full integration with Microsoft Active Directory, so role assignments can be based on existing Active Directory user accounts.
Patch Management
One of the most important maintenance chores in any IT shop is patch management. Although most vendors build some sort of automated patch-management solution into their wares, corporate environments typically require patches to be thoroughly tested, centrally managed and deployed in a controlled manner.
vCenter Server provides patch-management capabilities for the server virtualization infrastructure. The software not only patches vSphere servers, it can also patch specific versions of Windows and Linux OSes that are running as guest OSes. vCenter Server is even designed to automatically snapshot VMs prior to applying patches so as to facilitate rollback in the event that a patch causes a problem.
Although patch-management capabilities are built into vCenter Server, VMware also provides patch-management services through a product called vCenter Protect. vCenter Protect is available in Standard and Advanced editions. vCenter Protect is designed to offer a higher degree of flexibility for patch management than what's natively available in vCenter Server. Whereas vCenter Server is natively capable of patching vSphere servers and the OSes of VMs that are running certain versions of Windows or Linux, vCenter Protect supports patch management for Windows applications in addition to patching the OS. Furthermore, vCenter Protect supports patching both physical and virtual servers and offers agented or agent-less operations.
vCenter Protect Advanced offers the same capabilities as the Standard edition, but also offers antivirus protection and scripted operations. Another useful feature found in vCenter Protect Advanced is a power management function that allows you to schedule the shut down and startup of VMs. For example, this feature could be used to power down nonessential VMs after business hours or over the weekend, and bring those VMs back online when they're needed again.
vCenter Operations Management Suite
vCenter Operations Management Suite is a collection of tools that are designed to assist with the management and monitoring of large vCenter deployments. As you know, server virtualization is something of a delicate balancing act. On one hand, organizations need to achieve a high level of VM density so as to make the most of their server hardware investment. On the other hand, if system resource consumption isn't carefully managed, virtual server performance can become a serious issue.
Despite the importance of monitoring VM resource usage, it's unrealistic to expect to be able to manually monitor resource usage for large numbers of VMs. This is where vCenter Operations Management Suite comes into play.
vCenter Operations Management Suite is designed to collect performance and capacity information on your behalf and then turn that information into a useful set of recommendations. For example, the software is able to perform capacity analytics that can identify over-provisioned vSphere hosts. Once these hosts have been identified, the software allows you to use built-in tools to experiment with various what-if scenarios so you can analyze the effects of moving VMs to different hosts before actually doing it. In addition, the vCenter Operations Management Suite provides a series of real-time dashboards that allow you to assess VM health and performance.
Bundled Solutions
One VMware practice that potential customers need to be aware of is bundling. In some cases, VMware products are bundled together. VMware previously offered a product called vCenter Orchestrator as an automation solution. It's no longer offered as a standalone product and has been rolled into vCenter Server.
vCenter Configuration Manager can also be purchased as a part of a bundle. Although vCenter Configuration Manager is still available separately, it's included with the vCenter Operations Management Suite.
vCenter Configuration Manager is a tool for tracking compliance and facilitating change management. The basic idea behind this tool is that most organizations have certain standards in place for servers and workstations. These standards might be based on the corporate security policy, or they might exist as a way of ensuring compliance with regulations such as the Health Insurance Portability and Accountability Act (HIPAA), Federal Information Security Management Act (FISMA) or Sarbanes-Oxley Act (SOX).
vCenter Configuration Manager is designed to ensure that changes are applied to groups of servers or desktops in a consistent manner. Likewise, vCenter Configuration Manager can periodically assess the compliance state of individual physical machines or VMs by comparing them to the approved configuration. When it detects discrepancies, vCenter Configuration Manager can generate an out-of-compliance report and then automatically remediate the problem.
vCenter Site Recovery Manager
For organizations that have secondary datacenters, vCenter SRM is a must-have. SRM lets you create recovery plans that will allow VMs to fail-over to the secondary datacenter in the event that there are problems in the primary datacenter.
SRM does more than simply migrate VMs to an alternate datacenter. It allows for VMs to be provisioned with a new IP address once they've been moved. Similarly, VMs can be prioritized so that higher-priority VMs can take precedence in the event that the recovery datacenter has limited capacity. It's even possible to force VMs to boot in a specific order in failover situations.
vSphere Data Protection
Backup and recovery capabilities are important in any IT shop, but server virtualization compounds the difficulty of such operations. As such, VMware offers a tool called vSphere Data Protection Advanced that can help organizations manage backups within their virtual datacenter.
vSphere Data Protection Advanced was designed specifically for the task of backing up VMware VMs. That has led many organizations to consider vSphere Data Protection as their backup solution of choice. It's worth noting, however, that there are numerous third-party backup tools that are capable of backing up VMware VMs.
This was just a quick view of VMware's offerings. As you can see, they can be a bit overwhelming, to say the least. The products I've discussed here are the ones that are the most essential for creating an on-premises, single-tenant, server virtualization infrastructure. VMware offers server virtualization products beyond those that I covered here; Virtualization Review will check out VMware's vCloud line in the next issue.