Backup vs. Replication: What’s the Difference?

In today’s global, digital economy, businesses rely on data and application availability 24/7/365. Data protection is no longer a “nice-to-have” but a necessity for survival. This holds especially true for small and midsize businesses (SMBs).

Historically, SMBs believed they were small fish in a big pond and didn’t need the same data protection levels as their enterprise counterparts. However, times have changed, and any business is fair game for cybercriminals today. In fact, SMBs have become more susceptible to cyberattacks than their larger counterparts since their lack of preparedness equates to easy money for threat actors. Consequently, the financial and reputational losses that follow a data breach can force an SMB to shut shop for good.

With data protection becoming an increasing priority for IT decision-makers and professionals in the SMB world, two data protection practices you would typically come across are data backup and data replication. While often — and incorrectly — used interchangeably, data backup and data replication are not the same. Understanding these two concepts is critical when choosing an ideal data protection solution for your organization.

What is the difference between backup and replication?

Data backup and data replication are two overlapping yet different techniques that are vital for an organization’s data protection strategy. Let’s look at each of these methods in detail before discovering their similarities and differences.

What is data backup?

Backup is the method of copying physical or virtual files or databases to a secondary location for safekeeping so that they are not lost during a hardware/software failure, cyberattack, natural disaster, human error or any other common causes of data loss. TechTarget defines data backup as the process of “copying of physical or virtual files or databases to a secondary location for preservation in case of equipment failure or catastrophe.” Data backups help you create save points for your production data so that you can revert back to an earlier point in time in the event of a data disaster.

Through periodic copying and storing of multiple encrypted data copies, data backup ensures that business-critical data always remains protected and available for recovery. Any data you want to preserve, including documents, media and configuration files, operating systems, machine images, etc., can be backed up and kept for safekeeping. This can be done using various methods, and the copies are stored either on-premises or within the cloud.

What is the purpose of backup?

The primary purpose of backup is to create a copy of data so that it can be recovered in the event of a primary data failure. Primary data loss can happen due to a wide range of reasons, including hardware/software failure, data corruption or a human-caused event, like accidental data deletion or a cyberattack.

Creating and storing backup copies of your business data ensures that it is not lost in the event of unexpected incidents, thereby saving you from operational, financial and reputational consequences.

How does backup work?

Backup can be done in multiple ways. Based on the technique, backup can be classified into three groups — hardware, software and cloud:

• Hardware: One conventional way of backing up data is by leveraging your own data center and using a local backup appliance, where the data is stored on hardware in a data center you control. In this case, you are responsible for access and privacy of the backup copies. The downside here is that the physical hardware capacity will limit your storage capability. Hardware appliances are typically sized to accommodate local retention requirements and projected growth over several years. An event, such as a merger/acquisition, may result in significant growth in the total volume of data and require additional hardware or capacity.
• Software: Backup software is another type of local backup where data is stored on external hardware. The software can be integrated with the hardware or can be run separately. In this case, while the backup solution is scalable, it relies on the flexibility and scalability of the local hardware used, like magnetic tapes or disk-based hardware. 
• Cloud: Also called online backup, cloud backup backs up your data and transfers it over a public or proprietary network to a remote server away from the on-site location. Unlike the previous two on-site backup options, cloud backup doesn’t necessitate a high data center footprint or huge maintenance costs. The services can be used over a wide area network (WAN) and can be accessed from anywhere remotely. However, if not appropriately managed, cloud backups can encounter security and latency problems.

Backup can also be classified based on the approach used. There are primarily three types of backup, each with its own approach to backing up data. These are full, differential and incremental backups:

• Full backup: The simplest and most complete form of backup where a full copy of all the data on a specific host or a set of hosts is taken. It creates a backup of all data you wish to protect.
• Differential backup: Unlike full backup, differential backup doesn’t copy all the information but the data created, updated or altered after the last full backup.
• Incremental backup: Incremental backup copies data that has been modified since the last backup, whether it is full, differential or incremental.

Benefits of backup

Data is one of the most valuable assets of a business today, and losing it could result in devastating financial, legal and reputational consequences. For instance, the average data breach cost in 2022 was $4.35 million according to IBM. Such a financial setback, along with the loss of customer trust and scrutiny from regulation authorities, can force businesses into closure. Backing up your business-critical data ensures that it stays protected in the event of an unforeseen security incident.

Some of the other advantages of backing up data are maintenance of compliance standards, ease of data management, cost control, and less impact on operations and productivity.

Backup costs

The cost of data backup can vary from business to business, depending on the requirements. It depends on the backup technique you utilize, the schedule and frequency you opt for, and the storage and retention requirements you need.

What is data replication?

Data replication is the method of storing data in more than one site to ensure all information stays identical in real-time across those multiple sites. TechTarget defines data replication as “the process of copying data from one location to another. The technology helps an organization maintain up-to-date copies of its data in the event of a disaster.” Data replication ensures that you have multiple versions of the same data in hand if something happens to one of those. 

Data replication is carried out by storing data in two on-premises software instances or appliances, between appliances set in separate locations, or two entirely geophysically separated appliances through cloud-based services.

What is the purpose of replication?

The primary goal of data replication is to ensure that a business can continue its operations in the event of an IT incident. Data replication assures that data and applications remain readily available for users during an outage or emergency. On that front, you need to determine your recovery point objective (RPO) and recovery time objective (RTO) goals to implement an effective data replication strategy.

How does replication work?

Data replication is copying data from one host to another while maintaining real-time consistency with the data. It can be either synchronous (real-time) or asynchronous (scheduled):

• Synchronous replication: In synchronous replication, the data in the primary storage and the replica/target are replicated simultaneously to remain identical in near real-time. Synchronous replication is usually used for applications requiring instant failover to a secondary site when the primary site is unavailable. Failover to the replicated site is near instantaneous, resulting in little to no data loss. However, synchronous application necessitates a high-speed, low-latency network connection between primary and secondary sites, which makes it very expensive. Synchronous replication is thus not feasible for all workloads.
• Asynchronous replication: In the asynchronous method, replication happens on a scheduled basis during pre-determined intervals. There is a slight delay before the backup copy gets copied to the secondary site. However, since the replication can be scheduled during times of low network utilization, there’s more bandwidth for production. This is also less expensive than the synchronous method.

Benefits of replication

Data replication offers numerous benefits to businesses, such as:

• Resilience and reliability: Storing data at multiple sites ensures that users can access mission-critical applications even when one site is down. Since replica instances are exact copies of primary instances, you can rest assured that operational or performance levels do not falter.
• Improved accessibility: For businesses with multiple locations in different countries, replication allows quick access to data for the users by storing replicas in local servers near the users.
• Enhanced network performance: By dispersing the database among other sites, data replication lightens the load on the primary server.

Replication costs

Like data backup, data replication costs depend on various factors, such as the amount of data needed to be replicated, the frequency of replication and the storage required. Your RTO and RPO requirements will also significantly influence that.

Backup vs. replication: In summary

Data backup and data replication are two solutions with the same goal: to create a copy of your data. However, when data backup aims to ensure that the data is recoverable when necessary, data replication guarantees business continuity during a disaster.

Are backup and replication interchangeable?

While backup and replication are overlapping strategies, they are not interchangeable. While backup primarily focuses on the long-term retention of business-critical data, replication is a critical part of a disaster recovery (DR) plan that aims to ensure easy and swift resumption of operations following an outage. Organizations must leverage data backup and replication to realize a multifaceted data protection strategy that can ensure comprehensive data protection and business continuity.

Should I use backup or replication?

It is recommended that you use both data backup and data replication to realize comprehensive data protection. You should pair data backup with data replication to limit data loss and downtime from an unforeseen IT event. It will help you ensure that your business continues to operate and achieve its operational and business objectives during a disaster.

One golden rule the industry has been following traditionally for data protection is the 3-2-1 rule. The rule specifies that you need to keep 3 copies of any critical information (one primary and two backups) on 2 different media types (to defend against various types of risks) and 1 copy should be stored off-site (outside the local or physical site). This approach helps you have a data storage repository that can be relied on in any emergency.

Leveraging data backup and replication in tandem, along with a geo-redundant infrastructure, will help you achieve this. Geo-redundancy is the distribution of your critical data and infrastructures across multiple data centers in different geographic locations. This enables you to ensure that your mission-critical applications and workloads remain available and unaffected during a region-wide outage or disaster at your primary site.

A backup solution also comes in handy when retaining your business data for a long time for archiving and compliance purposes — particularly when longer RPOs and RTOs are tolerable.

Backup and replication with Unitrends

Whether backup or replication is your purpose, Unitrends can help you optimally achieve it.

With Unitrends, your replication target is either HOT or COLD.

HOT: If you want your backup copy to be recovery-ready, Unitrends has a series of robust backup appliances (physical or virtual) that can help you with that. Preconfigured with hardware, software and networking, these all-in-one solutions deliver one-click failover when your primary source is unavailable. In one easy step, you can define and schedule backups to meet your RTO and RPO requirements.

Unitrends also has a Disaster-Recovery-as-a-Service (DRaaS) solution that can help you substantially reduce the complexity and cost involved in protecting your critical workloads. Unitrends DRaaS can deliver swift spin-up of your data, applications and systems in the secure Unitrends cloud at a price considerably lower than what you would have to bear when you build and manage your own off-site DR. All you have to do is make a phone call when your primary source is down. Our state-of-the-art, award-winning support team will help you with the entire DRaaS process.

COLD: If you are looking for archival or retention of your business-critical data, Unitrends can also cater to that use case. We can land your backups on a storage destination separate from your on-premises appliance backup repository. This could be a disk, tape, storage devices like the storage area network (SAN) and network attached storage (NAS), or a public cloud bucket (such as AWS S3). Such backups are great for retention purposes and create an air gap from backups on the production/primary network. However, it is essential to note that your RTO will suffer since media must be retrieved or data must be downloaded to an appliance before it can be restored.

Get a demo now to discover how Unitrends can transform your data backup and replication strategies and help you achieve multifaceted data protection.