You’ve finally found what you’ve been searching for online. You add to cart, enter your payment information, and press “Place Order.” Then, your page freezes.
Now you’re left wondering: Did the order go through? Should you refresh the page? After an unsuccessful attempt, you’ll likely decide to shop somewhere else.
For the business, that interruption puts a potential sale and a customer relationship at risk. An outage can affect revenue, productivity, and trust, making availability and recovery important business priorities.
That’s where IT resilience and disaster recovery come in. The two terms are often used interchangeably, but they aren’t the same thing. Here’s how they differ, and what your business needs.
What’s the Difference Between IT Resilience and Disaster Recovery?
IT resilience is the broader strategy: your organization’s ability to keep services running through any disruption, using high availability, backup, disaster recovery, and cyber resilience together. Disaster recovery is one part of that strategy. It focuses on restoring systems and data after a disruption, and it’s measured by recovery time (RTO) and recovery point (RPO) objectives.
| IT Resilience | Disaster Recovery | |
|---|---|---|
| Scope | Overall strategy | One part of that strategy |
| Focus | Staying available during a disruption | Restoring systems after a disruption |
| Approach | Preventive | Reactive |
| Includes | High availability, backup, disaster recovery, cyber resilience | Policies, procedures, data replication, recovery sites |
| Measured by | Service levels and uptime | RTO and RPO |
| Checkout example | Checkout stays online when a server fails | Checkout is restored after a site-wide outage |
What Is IT Resilience?
IT resilience is your organization’s ability to maintain acceptable service levels when technology or business operations are disrupted. It brings together several forms of protection, including high availability, disaster recovery, backup, and cyber resilience, which protects systems and data from attacks like ransomware. Each one plays a part in helping your business handle disruptions.
For an online retailer, IT resilience means planning to keep checkout available, protect order information, and restore service if something goes wrong. Building resilience starts with understanding how an interruption would affect employees and customers, then putting protections in place to support those services.
So, how do you get those services back when something goes wrong? That’s where disaster recovery comes in.
What Is Disaster Recovery?
Disaster recovery, or DR, is a set of policies, procedures, and tools used to protect critical systems and restore business operations after a disaster.
Even a simple mistake or an unexpected power outage can leave your team unable to access essential applications. Disruptions can also come from cyberattacks, fires, or severe weather. Preparing for recovery means understanding what could go wrong and making sure your team knows what to do next.
RTO and RPO: Setting Your Recovery Goals
A good place to start is by asking two simple questions: How long can your business afford to be offline, and how much data can it afford to lose? These questions help establish two recovery objectives:
- Recovery Time Objective (RTO): The maximum amount of time your business can tolerate an outage.
- Recovery Point Objective (RPO): The maximum amount of data loss your business can tolerate when a disaster happens.
Think back to that frozen checkout page. How long could the business go without accepting orders? If it needed to recover its systems, how much recent order information could it afford to lose? Setting these priorities helps your team choose a recovery approach that fits your business needs and budget.
But having a plan is just the first step. Your team needs to practice it, too. [Regular testing](LINK TO FAILOVER CHECKLIST POST) helps everyone understand their responsibilities and the steps needed to restore operations. You don’t want the first time your team works through the recovery process to be during an actual outage.
How High Availability Fits In
Disaster recovery helps you come back from a major event, such as a site-wide outage or a regional disaster. But many disruptions are smaller and far more common: a single server fails, an application hangs, or a patch goes wrong.
That’s where high availability (HA) comes in. HA continuously monitors your applications and uses automatic failover to move them to a standby server when something fails, often before customers notice. For our online retailer, that’s the difference between a checkout page that freezes and one that keeps working.
High availability and disaster recovery work best together. HA keeps services running through local failures, and DR protects you when an entire site goes down.
Which Strategy Does Your Business Need?
The short answer: you need both, with disaster recovery as part of a broader IT resilience strategy. High availability, backup, disaster recovery, and cyber resilience all work together to keep services available and support recovery when disruptions occur.
To decide where to focus first, ask:
- Which applications are revenue-critical? Start with the systems your customers and employees depend on most.
- What are your RTO and RPO for each one? Applications that can’t tolerate downtime or data loss need high availability, not just recovery.
- Where do your applications run? On-premises, cloud, and hybrid environments each call for different protection.
- What can your team confidently manage? Clear procedures, regular testing, and tools that simplify recovery turn your strategy into something your team can put into action.
How SIOS Supports IT Resilience
At SIOS, we help businesses strengthen their IT resilience through high availability and disaster recovery solutions that protect critical applications. Our solutions support physical, virtual, cloud, and hybrid environments, giving businesses flexibility in how they protect their systems. SIOS has also earned the AWS Resilience Competency in the Design category.
SIOS LifeKeeper and DataKeeper support these goals in different ways. For businesses using Windows, SIOS DataKeeper Cluster Edition keeps copies of data up to date on multiple servers. If one server fails, Windows Server Failover Clustering can move the application to another server, where that data is ready to use. In Linux environments, SIOS LifeKeeper and DataKeeper work together to monitor applications, replicate data, and support recovery when a failure occurs.
Your customers count on everyday moments, like completing a purchase, to go smoothly. Your team needs a clear plan to keep applications available and restore service when something goes wrong. Making disaster recovery part of your broader IT resilience strategy helps you support both goals and protect the business people count on.
Not sure where your gaps are? [Talk to a SIOS expert](LINK TO CONTACT US) about your RTO and RPO goals.
Frequently Asked Questions
Is disaster recovery part of IT resilience?
Yes. Disaster recovery is one part of IT resilience, alongside high availability, backup, and cyber resilience. IT resilience is the overall strategy; DR is the part focused on restoring systems after a disruption.
What’s the difference between high availability and disaster recovery?
High availability keeps applications running through local failures, like a server crash, using automatic failover. Disaster recovery restores operations after larger events, like a site-wide outage, often from a separate location.
What are RTO and RPO?
Recovery Time Objective (RTO) is the maximum time your business can tolerate an outage. Recovery Point Objective (RPO) is the maximum amount of data loss your business can tolerate.
Is backup the same as disaster recovery?
No. Backup creates copies of your data. Disaster recovery is the broader plan, with processes and tools, for restoring systems and operations using that data.
How often should you test a disaster recovery plan?
Test regularly, and always after major changes to your environment, such as patches, upgrades, or new applications.
Author: Mia Reeves
