Assessing Disaster Recovery

Assessing Disaster Recovery 2017-03-23T11:23:24+00:00

Confidently test numerous disaster recovery scenarios and reduce the risk to critical business services. Gain an improved understanding of your disaster recovery cost/risk profile.

Develop your IT continuity and IT disaster recovery plans

In preparation for an audit you need to demonstrate to the Business Continuity folk your DR plan and whether it will work. With Sumerian Capacity Planner’s advanced modeling, you can conduct an infrastructure walk through of a disaster recovery event, simulate a datacenter or hardware failure, and demonstrate the impact.

As an example, a major public sector organization used Sumerian Capacity Planner to ensure that their technology refresh plans provided adequately for all likely disaster recovery scenarios. The modeling conducted also had an interim outcome, leading the client to adapt it’s current disaster recovery failover plans to only failover critical applications — until the new hardware was deployed.

The challenge

Without wishing to state the obvious, many organisations would cease to function effectively if their core IT services were down for a period of time. The possible causes of this downtime are too numerous to list but range from natural disasters to a simple lack of disk space.

The challenge facing organisations is how to manage the risk posed to their IT services, without spending ever more money planning and testing for a range of scenarios that may or may not happen. Unless you work for an organisation with limitless funds, your efforts to address these challenges through disaster recovery planning are necessarily constrained. So it becomes essential to manage the risk by planning for a discrete set of disaster recovery scenarios for priority services. However, the reality is you can still end up spending significant sums of money on (often) unneeded technology such as back-up datacenters (DC), cloud disaster recovery solutions, redundant servers and software tools to move replicate, mirror and failover workloads.

These ‘solutions’ can often neglect two particular but vital questions; “Do I have enough capacity in my target disaster recovery environment?” and “Do I have spare capacity elsewhere in my estate to provide disaster recovery contingency?”. These questions must be asked, and answered, for each disaster recovery scenario.

In order to reduce risk to the business with confidence, you must be able to quickly and clearly understand how capacity impacts your ability to respond to disaster recovery scenarios. Further, you must be able to test this at regular intervals to ensure the answers remain valid and use that insight to inform your investment and action plans.

Sumerian value add

Traditionally, many organizations have a primary (active) datacenter and a disaster recovery (passive) datacenter, acting as their backup and kept on standby. This costly approach restricts organizations to only utilizing 50% of their investment in compute and storage facilities, while the remainder of the infrastructure lies virtually dormant.

Sumerian Capacity Planner allows you to take a bolder approach, realizing significant savings over the traditional model and providing a clear picture of risk exposure that you can then calibrate based on your organization’s risk appetite.

By enabling organizations to confidently challenge the expensive active/passive DC approach, by making both DCs active (and therefore offering immediate offer benefits such as an increase in available capacity, reduced infrastructure spend and perhaps improved service performance), Sumerian Capacity Planner can support a quantifiable step-change in your organization’s approach to DR.

For example, in making both DCs active, an organization would need know if they had enough spare capacity in one DC, if the other fully or partially failed. Sumerian Capacity Planner allows you to quickly model DR scenarios and get an immediate answer on whether sufficient capacity exists.

As part of your IT disaster recovery planning, you may have identified 10 key disaster recovery scenarios – ranging from the loss of a DC to a host going down. These can all be rapidly modeled and tested in Sumerian Capacity Planner. Being able to model an unlimited number of scenarios and being able to test them regularly to ensure your IT disaster recovery plans remain valid in response to changing demand – is an essential capability in DR planning.

Sumerian Capacity Planner also provides a vendor independent evaluation of cloud disaster recovery solutions, that offer on-demand infrastructure. These are typically running on infrastructure in a co-located DC or public cloud (e.g. AWS, Azure, vCloud Air). Does the cloud DR solution provide enough storage and compute (CPU, memory, IO) for your workloads? Sumerian Capacity Planner can give you an evidence-based answer using current demand or projected growth.


One Sumerian customer had chosen an active/active strategy for their two main datacenters however they did not have a clear picture of the service demand and available capacity. This limited the promises they could make to the rest of their organization when it came to being able to restore services after a DR event.

They had a range of DR scenarios for their 1,500 workloads which prioritized their services into three categories. These were: critical services that must be failed over immediately (from one DC to the other) and powered on; second tier services that would be replicated to the other DC but not immediately powered on (due to capacity uncertainty); and a third category where no DR was implemented as service downtime could be tolerated.

Using Sumerian Capacity Planner, the client was able to model the failover of the critical services from one DC to the other – and see how much “DR headroom” they needed to maintain on the target infrastructure. Sumerian Capacity Planner was able to show that, due to increased memory demand, some of their critical services could not be accommodated in the target environment. It was obviously much better to know this in advance of any disaster recovery event and be able to mitigate the risk.

They were also able to remove uncertainty around the second tier services by using Sumerian Capacity Planner; to get a definitive answer on what could or could not be restored.

The customer could confidently test their disaster recovery scenarios, reduce risk to their critical business services, and provide the business with an improved understanding of the available disaster recovery capabilities versus cost.