Increasing the Availability of VMware Virtual Machines Is about And Instead of Or

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1 Enterprise Strategy Group Getting to the bigger truth. Solution Showcase Increasing the Availability of VMware Virtual Machines Is about And Instead of Or Date: September 2016 Authors: Jason Buffington, Principal Analyst; and Monya Keane, Senior Research Analyst Abstract: Organizations today are more dependent on their IT resources than ever. As a result, IT teams are transforming their data centers through server virtualization, even as they face increasing pressure to meet tight SLAs, increase agility, and reduce costs. IT infrastructures built upon VMware can increase the availability of the systems that matter most to organizations (without requiring any changes to long-term IT strategy or day-to-day IT management) by utilizing Stratus ftserver platforms as their hosts. Introduction For the past 15 years, almost every IT administrator handling data protection has had essentially one goal: Figure out how to move beyond reliably protectable to rapidly recoverable and by doing so, attain more durable IT. Thus, we have observed tape backups go to disk instead (or in addition to), and we ve watched as recovery point objectives (RPOs) and recovery time objectives (RTOs) decrease from half-days, to, to minutes (see Figure 1). 1 With some workloads today, the only acceptable objective is to be up and running again in seconds (at worst) or never go down (at best). Figure 1. Amount of Downtime Organizations Can Tolerate for High-priority Production Systems What is the amount of downtime your organization can tolerate from its primary production servers or systems before making the decision to fail over to a BC/DR secondary site or service provider for its high-priority applications. (Percent of respondents, N=391) 22% 22% 21% 14% 7% 5% 4% 3% 1% 0% No downtime ever Less than 15 minutes 15 minutes to less than 1 hour 1 hour to less than 2 2 to less than 4 4 to less than 6 6 to 12 to less than More than 24 Don t know 1 Source: ESG Research Report, The Evolving Business Continuity and Disaster Recovery Landscape, February This ESG Solution Showcase was commissioned by Stratus and is distributed under license from ESG.

2 Solution Showcase: Increasing the Availability of VMware Virtual Machines Is about And Instead of Or 2 When It Matters Most, Use the Appropriate Technology As Figure 1 shows: Only 13% of surveyed organizations can tolerate four or more of downtime, which is a typical time frame when one relies on a legacy backup solution. Modern backup solutions can typically provide recovery windows of one to four. Snapshotting, replication, and certain instant-recovery backup solutions can often address the recovery windows of 15 minutes to an hour. But what about those less-than-15-minute SLAs? Organizations continue to struggle to find adequate tools to meet them. It s important to remember that a wide range of SLAs is normal, based on the varying criticality of systems and data. And different SLAs should be achieved by using different technologies. In particular, when considering less-than-15-minute and zero-downtime SLAs, three approaches may be worth considering: Application-specific active-active monitoring. Some database applications (e.g., Microsoft SQL Server or Oracle databases) provide active-active replication asynchronously or synchronously between database server instances. In this manner, any client that cannot reach the initial database server immediately will instead transparently gain service from the alternate copy in near-real time. Hypervisor/failover (H/F) mechanisms. Mainstream hypervisors (e.g., VMware or MS Hyper-V) can rapidly move and restart a virtual machine from another host within the environment. Similarly, some third-party replication and failover products provide asynchronous replication coupled with an ability to resume functionality. Fault-tolerant (FT) infrastructure. By providing component-level redundancy in a single infrastructure framework such as an ftserver platform from Stratus Technologies, hypervisors and other operating systems become natively durable while remaining unaware of the advanced underpinnings of the infrastructure itself. To better understand how those three availability approaches fit into data protection as a whole, consider the ESG Spectrum of Data Protection and Availability (see Figure 2). This ESG solution showcase focuses on the two generalpurpose approaches: H/F mechanisms and FT infrastructure. Figure 2. The ESG Spectrum of Data Protection and Availability Understanding How Most High-availability Failover Mechanisms Work Most high-availability technologies are active/passive or fast recovery from failure models. In these cases, the production instance runs until something breaks, and then a standby instance boots up. Some recoveries may happen

3 Solution Showcase: Increasing the Availability of VMware Virtual Machines Is about And Instead of Or 3 automatically (e.g., database mirrors), while other platforms such as VMware vsphere require a restart of failed VM(s) on an alternate host after the initial failure. Regardless of terminology, these processes create uncertainty in the recovery: Data loss uncertainty There can be, and typically is, data loss between the active and passive nodes due to replication latency across the affected storage arrays, servers, and hypervisors. Boot-time uncertainty Passive instances are dormant until needed, so they have to boot up just like any other VM. Application start-time unpredictability Transactional applications, i.e., those using real-time logging combined with a database file, will often have unpredictable restart times as the logs are replayed (forward or backward) to return the database to a consistent state. Simply put, many third-party availability mechanisms yield the kind of unpredictable responsiveness during failover that might be seen if someone were to abruptly power off a running production server, and then restart it in place. In this case, one is restarting a near-current clone of a VM somewhere else and experiencing the variabilities associated with that action the restart of the virtual machine behaves almost as if there had been an abrupt power outage and subsequent server reboot. The process carries risks of 1) data loss due to asynchronous replication, and 2) unpredictable restart times as the hosted applications re-coalesce. The result is that while the VM might be running again in minutes, the time for the internal services, data, and ultimately user productivity, may have variable predictability that some will find unacceptable! The Challenges with Ensuring Availability of Mission-critical VMs A recently completed, Stratus-commissioned ESG survey of 250 IT decision makers reveals the specific challenges today s organizations experience in trying to attain availability in their virtualized environments. Figure 3 shows that the top reported challenges are that multiple hosts/licensing/interconnects are too expensive/complex. Also notable is that only 16% of respondents stated that everything runs reasonably well, presumably leaving over 80% of organizations looking for something different or as a supplement to what they are doing today. Figure 3. Challenges with Ensuring Application Availability in Virtualized Environments What challenges do you have with ensuring application availability within your organization s virtualized environment? What is your top challenge with ensuring application availability within your organization s virtualized environment? (Percent of respondents, N=250) Costs of additional virtualization hosts/storage too high Costs of additional application/os licenses too high Managing highly available apps is different than normal application management Networking/interconnects are burdensome or complex Failover time (RTO) is too long from failure to resumption Failover time is unpredictable vs SLAs Data loss is too high Other None of the above, everything runs reasonably well Don t know 1% 4% 4% 8% 8% 9% 11% 13% 14% 16% 16% 16% 18% 19% 18% 24% 24% 27% 31% Biggest challenge with virtualized environment availability All availability challenges with virtualized environment

4 Solution Showcase: Increasing the Availability of VMware Virtual Machines Is about And Instead of Or 4 Stratus Technologies Fault Tolerance with VMware More than three decades ago, Stratus became an acclaimed early innovator in fault tolerance and availability. The company s enterprise IT business was spun off in 1999, and by 2012, it had acquired Marathon Technologies, the other third-party IT resiliency vendor. That move essentially created a single source for always-on IT. Today, the Stratus ftserver represents the centerpiece of that IT durability. In its current iteration, ftserver is basically a server composed of internally redundant components that are abstracted by the operating system and/or hypervisor running on the hardware itself. The Service Component Stratus offers its customers a hard-to-duplicate level of service that can be especially beneficial to organizations lacking IT skills to maintain a multivendor storage network deployment. Call-home capabilities and high-quality logistical/technical support come directly from experts at a company with 36 years of experience in availability. There s great appeal in the idea that someone will always be able to help, especially when one is dealing with an With this architecture, component-level failure is no longer a concern. unplanned-downtime emergency situation. And, by running a VMware ESXi hypervisor on top of an always-on ftserver platform, one gains durability not otherwise achievable. Figure 4 depicts the difference between the expensive, complex way everyone else attempts to attain availability using external storage and commodity servers running VMware versus the Stratus approach. Figure 4. Contrasting a Typical Availability Approach (left) with the Stratus Fault-tolerant Architecture (right) Unlike a failover architecture with multiple hosts and replication between them, the Stratus architecture provides a single platform without any of the data-loss or downtime considerations that can come with a multi-host model. In doing so: ftserver hosted VMs will not suffer data loss due to corruption (during the outage/restart) or asynchronous replication (if used in complement), because the VM remains within the fault-tolerant ftserver infrastructure. ftserver hosted VMs won t (re)boot with uncertainty because recovery/durability is addressed in the underpinnings of the ftserver infrastructure without any interruption to the hypervisor or to the VM itself. Said another way, the VM does not restart.

5 Solution Showcase: Increasing the Availability of VMware Virtual Machines Is about And Instead of Or 5 Managing VMware on Stratus ftservers is no different than managing VMware on traditional commodity servers except that the VMs on ftservers don t go down due to host vulnerabilities. It is important to note that, with very little exception, managing VMware on Stratus ftservers is no different than managing VMware on traditional commodity servers except that the VMs on ftservers don t go down due to host vulnerabilities. To put it plainly, VMware plus Stratus gives customers a truly fault tolerant platform to run their missioncritical VMs on. Just as it is common for highly virtualized environments to have multiple hosts from multiple vendors, all of which are abstracted by the hypervisor and managed using a preferred management suite (e.g., vcenter Operations or System Center), ftservers running VMware simply appear as additional hosts, despite their always-on nature. That attribute makes them particularly well suited to quickly support the most vitally important applications in an organization. After the architecture is deployed and CPU compatibility between hosts has been ensured, then vadmins and IT operations staff will be able to move the mission-critical virtualized applications from a commodity host to the durable host using their normal management framework. The Bigger Truth For organizations looking for better availability for the virtualized systems that their businesses rely on, instead of duplicating the infrastructure, deploy always-on infrastructure hypervisor hosts that eliminate the need to fail over. Instead of whatever failover mechanisms that mainstream servers might run, higher-priority VMs simply keep running which certainly sounds like a much better alternative. Organizations that say, We haven t had a failure yet to justify using merely good-enough availability tools should know that statistically, they are due for such an occurrence, and it might hit a mission-critical server. Of course, few organizations have the luxury to deploy the best-of-the-best server infrastructure for every server in their environment. Most recognize that varied SLA levels demand varied levels of protection and availability: Most servers need something better than backup alone e.g., snapshots/replication. Some need better than any reactive approach e.g., failover/clustering. Some require continuous availability namely, Stratus ftserver. A lot of organizations still believe that their quest to solve an availability weakness must involve making an or decision between commodity offerings. Or, they expect complexity and costs that are unjustifiable. Those folks may want to reconsider their assumptions by considering how combining the capabilities of VMware and Stratus ftserver can give them a much better way to address their availability challenges. Organizations that believe solving an availability weakness requires an either/or decision should reconsider. VMware and Stratus ftserver can offer a better way to address the challenge. The VMware/Stratus ftserver approach is complementary, not competitive. Stratus has a longstanding partnership with VMware, and VMware s vsphere software contains Stratus code allowing it to recognize it is on a fault-tolerant server. Organizations won t have to change their hypervisor because VMware doesn t know that it s running on a better hardware platform than commodity servers. They won t experience data loss caused by replicating data between hosts. They won t have to change how they manage VMs: Most VMs may continue to run on generic hosts, but the really important ones should run on natively fault-tolerant hosts instead. For IT environments built upon VMware, adding an ftserver infrastructure raises the availability of the systems and workloads that matter most, without necessitating alterations to strategic direction or operational management.

6 Solution Showcase: Increasing the Availability of VMware Virtual Machines Is about And Instead of Or 6 All trademark names are property of their respective companies. Information contained in this publication has been obtained by sources The Enterprise Strategy Group (ESG) considers to be reliable but is not warranted by ESG. This publication may contain opinions of ESG, which are subject to change. This publication is copyrighted by The Enterprise Strategy Group, Inc. Any reproduction or redistribution of this publication, in whole or in part, whether in hard-copy format, electronically, or otherwise to persons not authorized to receive it, without the express consent of The Enterprise Strategy Group, Inc., is in violation of U.S. copyright law and will be subject to an action for civil damages and, if applicable, criminal prosecution. Should you have any questions, please contact ESG Client Relations at Enterprise Strategy Group is an IT analyst, research, validation, and strategy firm that provides market intelligence and actionable insight to the global IT community by The Enterprise contact@esg-global.com Strategy Group, Inc. All Rights Reserved. P