Guide to Server Management
Burning questions lead to best practices for virtual server management
Tips on tying physical and virtual server management together
By Denise Dubie
The hottest thing in server management these days is taming the virtual server beast.
Server virtualization makes it possible to run multiple applications and operating systems on fewer hardware resources, which appeals to many IT managers looking to improve utilization. According to a recent Forrester Research poll, respondents have virtualized about one-quarter of their servers and plan to have close to 50% virtualized in two years. As enterprise IT teams look to broaden their server virtualization deployments, it's important to get in front of the management challenges.
For those who are struggling with how to manage virtual machines, here are answers to six important questions.
1. What's so tough about managing virtual servers?
Some will tell you that managing virtual machines varies little from managing physical servers, and others will say it depends on what you're managing. But all agree you need to have a comprehensive management plan in place before widely deploying virtualization in production environments.
"Management is not a single discipline. It can range from business continuity planning to patch management," says Andi Mann, a research director at Enterprise Management Associates. In the case of business continuity planning, virtual servers could be considered easier to manage than physical servers, Mann explains, but when it comes to patching multiple systems, the virtual world introduces complexities. "You can't always be certain if all virtual systems are patched, and obviously that's a problem," Mann says.
Consistency and standardization also become a bigger issue when managing virtual servers alongside physical machines. The perks of virtualization include easy-to-deploy resources, and that demands IT managers have predefined configuration parameters for application and database servers, for instance. Experts say keeping configurations accurate and up-to-date becomes more critical in the virtual environment because configuration drift is more apt to happen on virtual machines. The same goes for patching.
"The focus shifts to managing templates and preventing drift," says Jasmine Noel, principal analyst with Ptak, Noel and Associates. IT managers would ideally create a standard template that details the operating system, vendor software, patch levels, custom code and more. The template would be maintained so that every new virtual server deployed remained consistent with the predefined standard. Patching would also become part of the template, Noel says.
Beyond maintenance and availability management, another key management issue is performance. The complexity of a virtual environment makes determining the root cause of performance issues a more daunting task, industry watchers say.
"Performance management becomes trickier because for the more difficult problems you'll need to understand how physical server issues manifest in the [virtual machines] and vice versa," Noel says.
While virtualization provides flexible resources, multiple virtual machines residing on one box compete for the same resources, and IT managers need to keep that in mind.
2. How do I curb virtual server sprawl?
Virtualization offers ease of deployment, which can become a bit of a Catch-22 scenario for IT managers. The faster servers can be provisioned, the more it seems they are in demand - and that quickly leads to too many virtual machines.
IT managers and industry watchers say controlling virtual server sprawl requires the same processes and auditing that would be used in physical server deployments to ensure only as many machines as needed get provisioned.
"We have it set up so that no one has the rights to add virtual servers without requesting them through IT," says Marc Kraus, manager of IT infrastructure at Merkle in Lanham, Md. "We run weekly scans as well to keep that in check."
While policy-based management and inventory tools can help IT stay on top of the number of servers, IT has to be disciplined about putting processes in place to prevent virtual sprawl from corrupting the success of a deployment.
"People know we are able to bring up a new virtual server and turn that around quickly so the requests have increased. We basically have had to push back a bit against server creep," says Albert Ganzon, director of network services and engineering at international law firm Pillsbury Winthrop Shaw Pittman LLP in San Francisco.
Industry watchers suggest adopting a server life-cycle management process in which a virtual or physical server's purpose and status from creation to retirement is tracked. Failure to curb lax deployment habits can exacerbate other challenges around managing virtual machines, such as patch management.
3. Are traditional management tools good enough for virtual servers?
Management vendors would answer, "Yes!" and for the most part, they have stepped up their support for virtual environments.
From systems management market leaders such as CA to data center management players such as BladeLogic, vendors have partnered with or built APIs into VMware's tools to enable the exchange of data and provide some metrics around the health and availability of virtual servers. Several vendors promise to provide virtual and physical management metrics such as CPU, disk and memory usage side by side, but IT managers need more than the basic information provided with some tools.
"Yes, my existing management tools work just as well with virtual servers as any other server. The difference, however, is you don't have the advantage of seeing the whole machine and manipulating that in the same tools you do the [virtual machines]," says Cars.com's Christensen. "Visual representations of environments and good dashboards are key in managing a virtual environment."
Start-ups such as PlateSpin, Scalent Systems, Veeam, Vizioncore and several others have emerged to fill the virtual management gap they say incumbent vendors can't address. For instance, some of the areas that start-ups focus on are identifying applications running on the virtual machines and gaining visibility into the requests and responses in the virtual stack. Innovative virtual server management tools can help IT managers more quickly identify which application on which virtual machines is performing poorly.
For IT managers who aren't ready to invest in specialized software for virtual management, there are things they can do to make their tried-and-true techniques better suited to a virtual environment.
For instance, Ganzon increased his investment in Network General products to monitor traffic to and from virtual servers. He coupled the traffic analysis from Network General (recently acquired by NetScout) with physical server performance metrics from Compuware's ServerVantage software.
4. Can tools that come bundled with virtualization hypervisors do the job?
The consensus is that the management tools that come bundled with VMware or Xen hypervisors won't cut it in a large virtualization deployment.
While the software provided with, say, VMware's hypervisor enables management of the hypervisor and that environment, industry watchers say the capabilities don't go much beyond availability to cover performance or other vendors' products.
Additionally, most networks have more than one type of hypervisor running, so there is a demand for a heterogeneous approach to virtual server management.
Plus the technology available today from virtualization vendors won't work as well when IT managers look to scale their virtualization deployments from dozens to hundreds of servers. While virtualization vendors are expected to differentiate themselves with management capabilities in the future, today's tools aren't up to snuff for large multivendor, multisite networks. Of course, that timeline doesn't mean IT managers getting started with virtualization can't put the tools to use.
5. Should I wait for Microsoft to deliver its virtualization hypervisor?
Whatever your opinion of Microsoft, you can't deny the company knows how to generate excitement over products. The operating system vendor's much-anticipated Windows Server Virtualization hypervisor technology, code-named Viridian, isn't expected to be released until 2008 at the earliest - which has some wondering if they should hold off their virtualization investment until then.
"Microsoft may want you to wait, but why wait? Whatever Microsoft does will be Microsoft-specific," Yankee Group's Hamilton say. Others agree, saying that Microsoft's product could make or break decisions in smaller Windows-centric shops but not for large heterogeneous environments.
"I'm unconvinced it is worth the wait for most large enterprises with a specific server virtualization project that they want done now," Noel says.
But if you are a Microsoft shop, you should take into consideration the vendor's plans. Waiting might be a bit counterproductive, but planning a short-term tactical approach until Microsoft reveals its bigger plans makes sense. While users question if Microsoft will broaden its reach to manage hypervisors other than its own, industry watchers are positive the vendor will couple its virtualization play with more management technologies.
6. What are my freeware and open source options for managing virtual servers?
Companies such as Hyperic and Veeam have released products designed to manage virtual environments. Hyperic, which released its Hyperic HQ for VMware software last year, built capabilities to extend the company's flagship software into virtual environments. The vendor wrote integrations into VMware's APIs and Virtual Center interface to discover both physical and virtual servers and incorporate virtual instances into an inventory of all systems. If something changes, the software detects it, updates the repository and alerts IT. HQ performs what the company calls "physical to virtual mapping" that shows IT managers the virtual machines and their hosts, as well as operating systems and applications running within the virtual machines.
In Veeam's case, the start-up is building a commercial software business off of the success of its freeware application. FastSCP 2.0 for VMware is a freeware file-management product that helps customers move virtual machines and copy instances from one server to another. FastSCP was originally released in October 2006 and "became the de facto standard for ESX file management," says Veeam President and CEO Ratmir Timashev.
Other industry watchers shy away from advocating freeware or open source applications for full-blown virtual server management.
"The risk in using freeware or open source is really low if it fills a gap in existing management tools, but I'd be nervous about trying to extend the capabilities or scale the application to cover an enterprise-level deployment. You don't want to get too far down the path with the freeware or open source application and realize it will not meet all the needs," Yankee Group's Hamilton says.