Mitigating the Risk of Downtime with Rollback

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Server White PaperMitigating the Risk of Downtime with Rollback

Aiming for Zero DowntimeBy ensuring uptime, businesses can improve their agility to meet customer expectations. Staying ahead of the innovation curve helps businesses meet competitive pressures. And as modern apps create explosive data growth, reducing downtime helps protect the mission-critical data that drives the business forward.

Alternatively, downtime can have devastating effects on the busi-ness. Unplanned downtime significantly reduces IT productivity, puts the business at legal or regulatory risk, and diminishes the reputation of the brand. Disruptions caused by unplanned down-time often directly translate to lost revenue.

It’s critical that digital businesses empower their IT organiza-tions with the technologies that not only protect the business from downtime, but also propel the business forward in today’s digital economy. Kelly Quinn, research manager for Datacenter Trends and Strategies at IDC, summarized the issue when she said, “While cloud use is growing with enterprises, particularly

in support of workloads that require time-sensitive, customer-facing and mobile service delivery, the internal datacenter will continue to be the primary enterprise infrastructure asset over the coming years.”1

The Costs of DowntimeThe costs of data center downtime are astounding. As reported in an Emerson Network Power study, the average cost of un-planned data center outages is nearly $9,000 per minute. The same study shows that downtime costs have increased 81% since 2010.2

Altogether, downtime is costing North American businesses an astonishing $700 billion per year, according to a 2016 study

How SUSE Linux Enterprise Server 12 Increases Data Center UptimeToday’s digital businesses are adopting new approaches to interacting with customers, competing for market share, and turning data into a revenue-generating asset. As our digital culture changes consumer expectations, it’s more important than ever to minimize or eliminate unplanned downtime.

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1 IDC,“TheProblemsofDowntimeandLatencyintheEnterpriseDatacenter,”December2015

2 EmersonNetworkPower,“2016CostofDataCenterOutages,”January2016

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released by IHS, Inc. For large enterprises, losses amount to more than $60 million annually.3

The research also shows that the costs of downtime detection and recovery pale in comparison to business disruption, lost revenue, and productivity losses. Business disruption, which includes cus-tomer churn and reputation damages, amounts to $256,000 per incident, representing the most expensive costs of downtime.4

The Root Causes of DowntimeThe first step in reducing the costs and damaging effects of downtime is determining their cause. According to the Emerson Network Power study, the top three causes of unplanned down-time are UPS system failure, cybercrime, and human error. In both the 2013 and 2016 versions of the study, 22% of survey respondents cited human error as the primary root cause of outages, indicating that no progress has been made in reducing potentially avoidable causes of downtime.

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3 IHS,Inc.,“TheCostofServer,Application,andNetworkDowntime:NorthAmericanEnterpriseSurveyandCalculator,”January2016

4 EmersonNetworkPower,“2016CostofDataCenterOutages,”January2016 Figure 2. Source:EmersonPowerNetworkstudy:2016CostofData

CenterOutages

Figure 1. Source:EmersonPowerNetworkstudy:2016CostofDataCenterOutages

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Server White PaperMitigating the Risk of Downtime with Rollback

Zero Downtime with RollbackParticularly where human error and cybercrime are the primary causes of unplanned downtime, IT organizations can reduce the effects to the business by quickly reverting to a prior state. One of the hallmark features of SUSE® Linux Enterprise Server 12 en-ables system administrators to do just that. Rollback increases

resiliency by rolling back a full system, including kernel files, quickly and easily with just one click. Automatic snapshot and rollback capabilities are integrated into the bootloader, making it fast and easy to jump back to a known state to protect the business from the risks of unplanned downtime.

Figure 3. RollbackprotectsagainstdowntimebyenablingITtorevertbacktoapreviousknownstate.

How Rollback WorksRollback is made possible by Btrfs, which is the default file sys-tem of SUSE Linux Enterprise Server 12. The first to commercially support Btrfs in 2012, SUSE built SUSE Linux Enterprise Server 12 on Btrfs recognizing that rollback is foundational to the needs of en-terprises who require an out-of-the-box, enterprise-grade solution.

With Btrfs as a foundation, SUSE Linux Enterprise Server en-ables rollback by creating snapshots from Snapper, a tool for Btrfs snapshot management. When the system administrator initiates a rollback, it starts with a list of read-only snapshots and the cur-rent root file system.

Figure 4. Beforeperformingarollback,thereareaseriesofread-only(RO)snapshotsandthecurrentread-write(RW)rootfilesystem.

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A read-only clone of the current root file system is then created.

Figure 5.

Figure 6.

The bootloader is now able to boot from Btrfs, which does not require a separate /boot partition anymore. This allows the sys-tem administrator to create snapshots which, aside from admin-istrative changes and package updates, also contain the kernel. This enables users to restore the entire operating system, not just single configuration files, as was the case in the past. If the system does not boot anymore and a rollback is required, the system administrator simply selects an older snapshot from the bootloader menu and boots the system from there.

The full system rollback includes two modes: reboot later and reboot now. With reboot later, the system administrator can

perform a rollback with the next reboot, indicating the ID num-ber of the optimal snapshot. For reboot now, the administrator first boots an old snapshot in read-only mode. Snapper rollback can then be used for a permanent change. In both cases, a read-only snapshot helps ensure that no data is lost.

Rollback takes a cautious approach to data management and will not affect certain log files, databases, and other files. All data is placed in subvolumes which are excluded from snapshots. Because a snapshot is always taken from the old root file system, no data is lost during rollback.

The system administrator can then select one read-only snapshot as the new root file system. This read-only snapshot is cloned in read-write mode as the new default.

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Server White PaperMitigating the Risk of Downtime with Rollback

About SUSE Linux Enterprise Server 12SUSE Linux Enterprise Server 12 is a world-class, secure, open-source server operating system. Built to power physical, virtual, and cloud-based workloads, it enables enterprise IT organiza-tions to support an agile infrastructure, deploy mission-critical services, and continuously improve infrastructure.

Using SUSE Linux Enterprise Server 12 infrastructure maximizes service uptime with cutting-edge Live Patching technology,

increases virtualization for application workloads, provides maximum security for all application needs, and creates cost-effective infrastructure with support for a wide range of hard-ware platforms.

For more information about SUSE Linux Enterprise Server 12, contact your local SUSE Solutions Provider, visit www.suse.com, or call SUSE at: 1-800-796-3700 (U.S. and Canada) or 1-801-861-4500 (worldwide).

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Contact your local SUSE Solutions Provider, or call SUSE at:

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