Managing Your Virtualized Environment: Migration Tools, Backup and Disaster Recovery The Essentials Series sponsored by Dan Sullivan
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Introduction to Realtime Publishers... i Ar ticle 1: The Business Case for Open Source Virtualization... 1 Cu rrent Trends in Virtualization Adoption... 1 Increasing Use of Virtualization... 1 The Emergence of Multiple Virtualization Options... 2 Growing Use of Multiple Hypervisors Within an Organization... 2 Ris ks with Single Vendor Virtualization... 2 Risk of Vendor Lock In... 3 Costly Changes in Licensing Structure... 3 Limited Tools Provided by Vendor... 4 Be nefits of Open Source Virtualization... 4 Cost Benefits of Open Source Virtualization... 4 Maturity and Scalability... 5 Integration with Existing Infrastructure... 5 Summary... 5 Ar ticle 2: Migration to Open Source Virtualization... 6 W ays of Deploying Virtualization... 6 Virtualized Servers... 7 Private Computing Clouds... 7 Virtual Desktop Environments... 7 Te chnical Features to Assess in Virtualization Platforms... 8 Cross Platform Support... 8 Performance and Scalability... 8 Security... 8 Live Migration Support... 9 High Availability... 9 Additional Advanced Features... 9 ii
Ma nagement Features to Assess in Virtualization Platforms... 9 Management Console... 10 Self Service Support... 10 Operations Automation... 10 Using Backup Solution to Support Migration... 11 Summary... 11 Ar ticle 3: Ongoing Operations: Backup, Disaster Recovery, and Data Protection... 12 Need for Virtualization Aware Backups... 12 Ke y Technical Features to Consider... 13 Support for Multiple Virtualization Solutions... 13 Perform Live Snapshots... 13 Support for Migration... 13 Support for Compliance... 14 Support for Compression... 14 Disaster Recovery and Data Protection Considerations... 14 Ma nagement Considerations... 15 Cost and Licensing Model... 15 Centralized Management... 15 Support for Existing Storage Media... 15 Policy Based Backups... 16 Deduplication of Data... 16 Support for Hybrid Virtual Physical Environments... 16 Summary... 16 iii
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Article 1: The Business Case for Open Source Virtualization Virtualization is one of the single most important technologies for efficiently operating servers. It should not be surprising to learn that open source options are available for this essential technology. Just as open source initiatives have produced widely used operating systems (OSs), databases, application servers, and even desktop applications, there are open source options for virtualization as well. Do you wonder if open source virtualization is right for your business? Perhaps you are concerned about how it might fit with your existing virtualization platforms? Are you unsure about why you should even consider open source virtualization? In this first part of the series, you will learn about: Current trends in virtualization adoption Risks associated with single vendor virtualization Benefits of open source virtualization The benefits of virtualization are well established, as are the benefits of open source software. Now it is time to consider in detail the benefits of the two combined. Current Trends in Virtualization Adoption A few trends are apparent in the options and use of server virtualization platforms: Increasing use of virtualization Emergence of multiple virtualization options Growing use of multiple hypervisors within organizations These trends reflect the economic and business benefit of virtualization to the enterprise. Increasing Use of Virtualization It is no surprise that virtualization adoption is on the rise. With virtualization, organizations can increase the overall utilization of their servers. Prior to the development of hypervisors that allowed multiple OSs to run together on a single server, businesses often followed a one application one server rule of thumb. This was not because one application demanded all the resources of a server but because applications often required specific configurations, OS versions, or code libraries. Trying to run two or more enterprise applications on a single server could be more trouble than it was worth. For example, one of the applications might require an OS patch but the other application might break if that patch were applied. Rather than find out too late about unanticipated dependencies between an OS and application, IT professionals often opted for the one application one server approach. 1
Server virtualization solved the unanticipated dependency problem. With a hypervisor allowing multiple OSs to run on a single server, systems administrators could host multiple applications, each with their own optimally configured OS, on one server. Systems administrators are not even constrained to run the same OS on virtualized platforms. Windows Server and Linux can operate on the same physical server as easily as can multiple versions of the same OS. The Emergence of Multiple Virtualization Options One of the advantages of a maturing software technology is that multiple vendors will promote their products. In some cases, a single vendor may come to dominate such markets. For example, in the early days of personal computers before Microsoft s DOS users could choose PCs that ran a different OS; later, Windows dominated the PC market. In the early days of the relational database market, new and existing software vendors offered viable products to a growing community of users. Virtualization appears to be following the trajectory of relational databases more so than that of PC OSs. Businesses have choices when it comes to virtualization. They can choose from vendors specializing in virtualization, from large scale software vendors or from open source options. All have advantages and disadvantages, so, like so many IT decisions, the choice of virtualization is driven by your requirements and budget. Growing Use of Multiple Hypervisors Within an Organization Virtualization does not require you to use a single hypervisor for all your virtualization needs. An IT department can run their email servers and LDAP servers on one hypervisor while choosing a different virtualization platform for their Web servers and application servers. The marginal costs of learning to manage two different virtualization platforms can be easily outweighed by the benefits of choosing the optimal hypervisor for each requirement. Another consideration is the risks associated with using a single virtualization product. Risks with Single Vendor Virtualization There are certainly conveniences that come with using a single virtualization platform. For example, you will have a single toolset to work with and one licensing model to understand. These are also two examples of the risks associated with using a single software provider. 2
Risk of Vendor Lock In When you select a single software provider for any enterprise application, that choice is often followed with decisions that promote vendor lock in. This decision is not intentional who would want to limit their future choices? The driver is economics. Once you have selected a virtualization platform, you will build an array of supporting systems and procedures for deploying virtual machines (VMs), managing images, reporting on usage, and performing other management tasks. You could design these in sufficiently abstract ways that enable you to swap in or out any virtualization platform, but we rarely do. Why? The cost of such efforts is difficult to justify when deploying a single virtualization platform. It is faster and less expense to use the tools provided with your chosen virtualization platform. Costly Changes in Licensing Structure Another aspect to factor in when considering the use of a single virtualization platform is that vendors may change their licensing model at any time. There are many ways to license virtualization software: Number of physical servers Number of virtual servers Amount of memory in physical servers Amount of memory allocated to VMs Number of CPU cores in a physical server Number of CPU cores allocated to VMs When a vendor changes the way it charges for licenses, the change can cause substantial modifications in your charges. For example, if a vendor starts with a charge based on physical servers, you will likely optimize your licensing according to that model. For example, you might minimize the number of physical servers you purchase while maximizing the number of CPU cores and amount of memory. If the vendor then changes the licensing model to be based on the amount of memory or number of CPU cores, you might find yourself with a larger virtualization bill than you planned for. Once a vendor makes such a change in licensing structure, you have several choices: Pay any additional licensing charges Change your strategy for deploying VMs to lower your costs under the new pricing scheme Change virtualization platforms The first option might be the only choice in the short term. Changing your strategy for deploying VMs might require changes in your hardware, which can be too costly to consider, at least during the useful lifespan of your current set of servers. Changing virtualization platforms might be the best option but will take time to plan and execute. 3
Limited Tools Provided by Vendor A third factor to consider about risks associated with working with a single virtualization platform is the potential limited toolset provided by the vendor. Tools are essential for deploying, managing, and monitoring your virtualized environment. If vendor provided tools do not offer the functionality you need, you might find yourself scripting your own tools, which of course, you will then have to maintain. As you evaluate your virtualization platform options, consider the tools provided by the various frameworks, including those for: Deploying VMs Creating VMs Monitoring performance and altering system managers to specific events Generating utilization and billing information Working with a single vendor for any enterprise application has appeal, but there are risks to consider too. Fortunately, there are several virtualization platforms available today, including open source options, that give you the choice of using multiple virtualization platforms in your organization. Benefits of Open Source Virtualization Open source virtualization should be considered because of the potential benefits of adding it to your virtualization environment. Some of the key considerations are: Cost Maturity Scalability Integration with existing infrastructure These benefits can be realized without limiting yourself to a single virtualization provider. Open source virtualization can be considered in addition to commercial virtualization products. Cost Benefits of Open Source Virtualization Perhaps the most obvious benefit of open source virtualization is cost. With open source products, there are no licensing charges, so the cost of working with these products is minimal. The open source model also limits the risk of increased future costs unlike commercial vendors that might change their pricing scheme after you have made substantial commitments based on the existing licensing model. With open source software, you have the choice to purchase maintenance support from commercial providers. This supplement can provide the benefits of both open source and commercial offerings: low initial costs with assurances of support in the future. 4
Maturity and Scalability Open source virtualization products are widely used and have demonstrated their maturity and scalability. Open source hypervisors have demonstrated high levels of performance and the ability to run large numbers of VMs in the industry standard benchmark SPECvirt. Open source hypervisors also deliver performance comparable with bare metal performance for widely used enterprise applications. Integration with Existing Infrastructure Open source virtualization platforms integrate with existing infrastructure. Commonly used OSs from Microsoft and open source OSs run within open source hypervisors. Enterprise applications from major vendors such as Microsoft, Oracle, and SAP are running within open source virtualization environments. Open source hypervisors do not come with restrictions on how they can be used in the enterprise. In fact, the largest public cloud provider uses an open source virtualization hypervisor in its cloud. Summary Virtualization is a mature technology. Organizations are using virtualization to improve the efficiency of their IT operations and provide greater flexibility in how they deliver business services. They are also increasingly using multiple virtualization platforms. Doing so allows users to choose the best virtualization solution for their particular requirements without the risk of single vendor lock in. Open source virtualization has demonstrated its cost advantages as well as its maturity and scalability without sacrificing integration with existing infrastructure. 5
Article 2: Migration to Open Source Virtualization Open source virtualization will fit well in many organizations. One of the first considerations is how to migrate from currently deployed hypervisors to an open source platform. There are multiple ways to deploy virtualization and, in some cases, the best option is a combination of multiple hypervisors. In order to realize the greatest benefit of open source virtualization, you should keep in mind a number of factors: Ways of deploying virtualization Technical features to assess in virtualization platforms Management features to asses in virtualization platforms Use of backup solutions to support migration By weighing the relative importance of features against your requirements, you should be able to find a combination of virtualization platforms and migration procedures that fit your needs. Ways of Deploying Virtualization Virtualization has fundamentally changed the way we deploy applications and deliver services. It has decoupled applications and even desktops from hardware. In the process, it has created operating system (OS) environments that are sufficiently removed from hardware dependencies that we no longer need to think in terms of one server to one application. Instead, we can think of servers as a pool of resources for running virtual machines. VMs can move between physical servers as needed to optimize performance, consolidate VMs, and minimize the number of physical servers running at any time. The ability to decouple an OS from dedicated hardware promotes at least three ways of deploying virtualization: Virtualized servers Private computing clouds Virtual desktop infrastructure These deployments implement a wide array of services that all use the same fundamental technology. 6
Virtualized Servers When a single physical server is used to run multiple OSs, we call that a virtualized server. You deploy virtualized servers when a physical server has more capacity than is needed by a single application or set of applications that would run on a single instance of an OS. For example, you might have a lightly used collaboration server and a moderately used employee portal that you need to deploy. One runs under Windows while the other runs under Linux. Neither requires the full capacity of one of your servers. This scenario is typical for a virtualized server. Private Computing Clouds Private computing clouds extend the way we think about virtualized servers. A computing cloud (or simply cloud ) is a set of servers and supporting infrastructure dedicated to running VMs. In the virtualized server model, we tend to run the same VMs for extended periods of time, such as months or years. Clouds support more frequent changes in the number and type of VMs deployed. For example, a retailer might update their data warehouse every night. Stores upload their daily transactions to a staging area where the data is processed and loaded into the data warehouse. This setup creates a peak demand for computing resources at night with no demand during the day. Rather than dedicate servers to this process, a better model is to deploy VMs during the demand period and then release the physical servers to run other jobs during the day. Cloud infrastructure is optimized for this kind of frequent change in VM deployment. Virtual Desktop Environments Virtualization technology works well with desktops as well as servers. One way to work with a virtualized desktop is to run a hypervisor on the desktop and host two or more OSs. This setup may be appropriate for developers or others who can make use of multiple OSs on the same desktop. Another practice provides virtual desktops to client devices while running the desktop OS on a server in a data center. This configuration can be especially appealing to businesses whose employees want to work with personal laptops, tablets, and smartphones. With virtualized desktops, centralized IT can configure VMs for desktops with all the security controls they require. Virtualization platforms are commonly used to virtualize servers, and the rate of adoption of cloud computing and desktop virtualization is increasing. As you consider how you will use virtualization, be sure to evaluate the technical features of the platforms. 7
Technical Features to Assess in Virtualization Platforms There are a range of technical features that can distinguish virtualization platforms. Some of the most important are: Cross platform support Performance and scalability Security Live migration support High availability Additional advanced features Some of these features may be more relevant to your requirements than others; their importance should be weighted accordingly. Cross Platform Support Hypervisors used for server virtualization should support multiple OSs on the same physical server. One of the advantages of virtualization is that it allows you to arrange multiple VMs across servers to optimally load each server. Being constrained to running only a single type of OS on a hypervisor reduces the chances of finding an optimal configuration of VMs. Performance and Scalability One of the ways to measure performance of a hypervisor is to compare it with a direct implementation on a bare metal server. For example, if you can run a database application benchmark in 100 seconds on a database deployed to an OS running directly on a server, and that same benchmark takes 120 seconds when deployed to a comparably configured VM, you have a 20% performance penalty. For obvious reasons, you want to minimize this penalty. Scalability is also a key consideration. The more VMs a hypervisor can support, the better the scalability. It is not unusual to have virtual servers that place minimal demand on underlying hardware. In such cases, it makes sense to run as many of these low utilization VMs as possible on a single server. If the hypervisor requires substantial overhead for each VM, scalability will be limited. Security Most security controls will be implemented at the OS level, but security is still an issue for hypervisors. It is important to logically isolate VMs so that an adverse event on one of the hosted VMs does not affect any other VM running on the same physical server. 8
Live Migration Support The load on servers running VMs will change over time. In especially dynamic environments, there might be physical servers with multiple VMs running heavy loads while other servers have relatively light loads. Ideally, the virtualization platform would allow VMs from one server to migrate to another server without shutting down the VM. With this type of support for live migration of VMs, resources can be continuously reconfigured for optimal performance. Migrating VMs can also result in better consolidation so that fewer physical servers have to be running at the same time, saving on power and potentially cooling costs. High Availability Businesses that depend on the constant availability of applications and services should assess the high availability features of virtualization platforms. Hardware fails and OSs hang. Virtualization platforms that can detect hardware and OS failures and automatically restart VMs on other hardware can enable high availability services. Additional Advanced Features In addition to high level technical features, such as high availability and security, there are lower level implementation details that should be considered: Advanced memory management features Network interface card (NIC) teaming to share traffic between physical and virtual networks across multiple NICs Support for multipathing, allowing for data transfer paths to storage Power management features to reduce power consumption when possible Hardware and guest OS certification Given the complexity of virtualization platforms, it would be understandable to focus on technical features as the prime differentiator between your options. That would be a mistake. Be sure to consider the management features as well. Management Features to Assess in Virtualization Platforms The day to day operations in a virtualized environment will have as much impact on the business bottom line as many of the technical features. Look for virtualization platforms that provide: Management console Self service support Operations automation The objective of this assessment is twofold: first, to determine what parts of day to day operations can be automated and second, understand what features are in place to streamline the remaining manual tasks. 9
Management Console A management console is a particularly important tool for systems administrators. This console should provide a single point of access for managing VM images, monitoring performance, viewing reports, and responding to alerts. VM image management can be time consuming without proper tools. Images will need to be patched from time to time. New images will be added to the image catalog and others will be removed. A management console should support searching metadata associated with images (for example, OS version or patch level) so that administrators can quickly isolate particular images. Self Service Support The more end users can do for themselves, the better. Self service reduces IT administration costs. It can also improve the response time between recognizing the need for a change and the time to actually finish implementing the change. Self service features should be made available on an as needed basis. A user s role in the organization should dictate their level of access to support functions. For example, developers might be granted the right to create a new VM image while most other users are not. Operations Automation Operation automation features overlap with some of the technical features described earlier. Some of the most significant are: Load balancing Power savings Image management Network and storage management These automation features can significantly influence the cost of ongoing operations. Load balancing in conjunction with power saving features can optimize the number of servers running at any time. Image management features can help ensure that images are cloned rapidly and snapshots are created and stored in case you need to roll back to an earlier state of the machine image. In the likely event that existing management features and reporting do not meet all of your needs, you might be able to implement a custom solution if a centralized API is available. Be sure to assess the functionality provided by the virtualization platform s API. Organizations that make use of multiple virtualization platforms can realize further savings by streamlining migrations with the right backup solution. 10
Using Backup Solution to Support Migration Backup solutions designed to support VMs can be particularly useful for migrations. You might be migrating from physical as well as virtual servers, so look for backup solution that can migrate: Physical to virtual servers (P2V) Virtual to virtual servers (V2V) Virtual to physical servers (V2P) The next article in this series will delve into detail about the need for virtualization aware backups and key backup technical features to consider. Summary Migrating to open source virtualization presents a number of opportunities. These choices are driven in part by the different ways you can deploy virtualization for example, as server virtualization, private clouds, or desktop virtualization. When migrating to or adopting another virtualization platform, consider both the technical and management features provided. 11
Article 3: Ongoing Operations: Backup, Disaster Recovery, and Data Protection Maintaining your virtualized environment will require attention to backup, disaster recovery, and data protection. Although there are many similarities between these operations in non virtualized and virtualized environments, there are significant differences as well. This concluding article on managing virtualized environments will examine: The need for virtualization aware backups Key features of backup solutions Disaster recovery and data protection considerations Management concerns related to backup, disaster recovery, and data protection The purpose of this article is to help you understand how to choose and deploy a backup solution that will meet your particular requirements. Need for Virtualization Aware Backups A typical backup solution for non virtualized servers includes a software agent that runs on the server and transfers data to a backup server, which in turn, writes data to a backup device. In theory, this setup might appear to work for a virtualized environment, however, this process can cause challenges in a virtual environment. To deal with these challenges, you need a virtualization aware technology so that you can save on resource consumption, whether storage or network related. If your backup solution is licensed on a per agent basis, the cost of licensing your backup solution could increase dramatically. Before you deploy an agent based backup solution in a virtualized environment, consider the licensing structure; site licensing or physical server based licensing will not constrain your ability to deploy additional virtual machines as needed. 12
Key Technical Features to Consider Virtualization awareness is just one of the features that a backup solution should provide. In today s enterprise, backup solutions have to support heterogeneous environments, provide features required for regulation compliance, and help control costs of backup storage. When evaluating backup solutions, consider: Support for multiple virtualization solutions The ability to perform live snapshots Support for migration Compliance issues, especially encryption Support for data compression These features will affect both the cost and efficiency of backup operations. Support for Multiple Virtualization Solutions Enterprises have long supported multiple operating systems (OSs) so it is no surprise that they would also deploy multiple virtualization platforms. Organizations choose virtualization platforms and OSs based on different sets of requirements, availability of applications, cost, and other factors. Enterprises rarely have a wide range of disparate backup requirements. A single comprehensive backup solution should be sufficient for most organizations. That is, as long as the backup solution supports multiple virtualization environments. Perform Live Snapshots There was a time when you could assume that most of the demand on your applications would occur during business hours. This situation left the night as the ideal time to perform backups. Those days are gone. Applications are used continuously. The amount of data requiring backup continues to grow to the point where traditional nightly backup windows are not long enough to complete backups. Another approach is needed. With live snapshots, you can quiesce the VMs and make snapshots at any time. Creating a snapshot happens quickly, so there is minimal impact on VM performance. This ability to make live snapshots is essential to allowing VMs to continue operations while ensuring that sufficiently frequent backups are always available. Support for Migration Backups are primarily used to protect systems in the event of a failure, but there are other uses as well. A backup of a VM can be used to migrate a VM to other physical servers running a hypervisor or to a physical server. This capability makes VM backups a useful tool for supporting migration that is, as long as the backup solution supports restoring a VM to a device or hypervisor different from it source device or hypervisor. 13
Support for Compliance Businesses in healthcare, financial services, and government as well as publically traded companies are subject to a number of regulations designed to protect the confidentiality and integrity of business and personal information. Many such regulations require security controls to mitigate the risk of disclosing private and personal information. These typically require that data is encrypted both when it is stored on devices and when it is transmitted over networks. If a backup tape or drive were lost or stolen, it could constitute a data breach under regulations. Backups that provide the ability to encrypt data as it is backed up can reduce and virtually eliminate the risk of a lost backup tape leading to the disclosure of private information. Support for Compression VMs must keep all of their state information and data uncompressed when executing. When stored on a backup device, however, the VM can be compressed. This setup can save substantial amounts of storage and ultimately reduce the cost of operating and protecting your virtualized environment. Backups are essential in virtualized environments just as they are in non virtualized environments. An appropriate backup solution should include support for multiple virtualization platforms and rapid backups using snapshots as well as support for migration, compliance, and compression. Disaster Recovery and Data Protection Considerations Backups are a basic building block of disaster recovery, but disaster recovery brings additional demands on how you use those backups. Imagine your data center is lost to a fire, flood, or other natural disaster. You have backups of all of your virtualized servers at an offsite location. You ve secured a disaster recovery site with a mix of hardware. Now comes the real test. Can you restore your operations with full VMs restored to the same hardware configuration, full VMs restored to different hardware configurations, or selectively restore files from VM backups? These are all scenarios you could encounter during a recovery operation. In fact, unless you have an identically configured recovery site, you will probably find yourself restoring to a different set of hardware. When selecting a backup solution, be sure to consider the range of possible options you might need in a disaster recovery situation. You would not want to find out during a restore operation that your backup solution does not restore to dissimilar hardware or requires you to restore a full VM just to restore a few files. 14
Management Considerations When it comes to backups, disaster recovery, and data protection, there is no shortage of management considerations. In some cases, there is overlap between technical and management considerations. Some of the most important features to assess in a backup solution, at least from a management perspective, include: Cost and licensing model Support for centralized management Support for existing storage media Deduplication of data Policy based backup Support for hybrid virtual physical environments These factors all have the potential to impact the cost and efficiency of operations. Cost and Licensing Model As with virtualization platforms, there are many ways to price a backup solution. Site licenses and per physical server licenses are probably the easiest to plan around. When license charges are based on the number of VMs using the backup system, estimates are more difficult. For example, would you pay per backup agent deployed to a running VM? Or perhaps by backup agent deployed to a VM image regardless of whether it is running? Be sure to understand the licensing model as part of your evaluation to avoid unexpected surprises down the road. Centralized Management Centralized management features can streamline backup operations. Look for backup systems that support: Remote agent installation Centralized backup plans Monitoring and reporting Each of these features can help reduce the administrative overhead associated with performing and managing backups. Support for Existing Storage Media Do not overlook the fact that your business might have a substantial investment in backup storage media. If you have to invest in a different media in order to use a new backup solution, be sure to factor that cost into your decision. 15
Policy Based Backups Not all data or applications are equally valuable. Some data and systems should be backed up more frequently than others. Consider the plight of a systems administrator who has to code a script with exceptions to the rules for backups. As new VMs are deployed, the systems administrator will have to add the new VM to the proper script. As users change their requirements for backup, the systems administrator will have to delve into scripts again to make changes. A more efficient method is to define policies that describe the backups that are to be performed based on characteristics of the target systems. Deduplication of Data Data is often redundant. Backing up every block of data, even if an identical block has already been backed up, is a costly option. Backup vendors have implemented deduplication technologies that detect duplicate data blocks within a backup. When a duplicate is detected, a reference to the first copy of that block of data is inserted into the backup instead of inserting another copy of the data block. Substituting a reference to a block of data for a block of data itself can substantially reduce the volume of storage required for backups. Support for Hybrid Virtual Physical Environments Organizations might find that they need to support a combination of virtualized and physical servers. For example, they might license enterprise software that is supported only when running on physical servers. In such a scenario, it s reasonable to deploy applications to VMs only when there are no restrictions on virtualization. Ideally, the business should not need two backup solutions, one for their virtual servers and one for their physical servers. Summary Backup, disaster recovery, and data protection are critical considerations in virtualized and physical server environments. When assessing the right backup solution for your organization, remember the need for virtualization aware backups as well as key technical and management features of the solution. Also keep in mind the additional requirements imposed by disaster recovery and other data protection considerations. 16