Backup versus Replication – What’s the Difference
Data backup and data replication are two data protection solutions that both have the same goal: to create a copy of your data. However, what is the difference between these two solutions? Let’s take a look at how each solution works, where they’re used, and what their benefits are.
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What is data backup?
A data backup ensures that business data remains protected through periodic copying and storage of multiple compressed and encrypted copies. Backup copies can be stored on on-premises storage or in the cloud.
Data can be backed up by any number of methods such as: disk-to-disk; disk-to-tape; tape-only systems; online backup systems like StoneFly CDR365.
What is data backup used for?
Business data can be backed up for any number of reasons, here are some of them:
- Before any business activity (such as manual or computerized data entry) takes place.
- After a disaster strikes in order to restore the organization’s computer system(s), server(s), database(s), and virtual machine(s) to a known good state.
- To ensure recoverability and/or regulatory compliance should corruption, loss, or destruction of the primary data occur.
- In an online backup system, disk images are cloned on storage media that forms part of the backup infrastructure. These clones represent the exact copy of the source volume at any point in time; this allows offline copies to be taken without disturbing production workloads while simultaneously ensuring that rapid recovery times are achieved when combined with automated failover options and thin restoral technology.
Restore Data Using Data Backups
Data is restored from backups by following these steps:
1. Restoring data from a backup disk image.
2. Decrypting the data on the backup disk image.
3. Mounting the data on the backup disk image as read-write (rw) to ensure that it can be used as needed.
4. Consulting with an IT professional to find out whether any additional steps need to be taken before you can use the data or if you can simply use it as-is, such as configuring necessary settings or synchronizing data with other systems in your organization’s environment.
What is Data Replication?
Data replication works in complementary partnership with data backups, offering a way into the future by continuously copying live production data, using asynchronous or synchronous methods. It processes a degree of loss or corruption by remote storage that can be managed automatically upon detection of an issue with the originating volume.
Replication can occur on storage media that’s right for the job; this means that it usually employs larger capacity devices than your backups because of its continuous operation requirements. That said, it also operates at near-real time speeds versus slower speed disk-to-disk backup Window and Tape technologies used for data backup purposes.
Synchronous and Asynchronous Replication
Synchronous replication is continuous and in real-time. In this for of replication, a secondary storage device is configured as a mirror of an original production volume and any changes to it are replicated on the secondary device immediately after they occur on the primary volume that’s being mirrored. This application ensures that your data losses or corruption will be limited to minimal amounts when compared to asynchronous replication.
A drawback of this method is that it’s expensive and complex to set up. It also requires the secondary storage device to be in a near-continuous state of operational readiness.
If you’re using an online backup system such as StoneFly CDR365 or a storage concentrator such as StoneFly StoneFusion™ or SCVM™, you’ll need a highly available mirror disk for every primary disk that’s being mirrored by the system (regardless of whether or not they are currently being used). If you have two active disks on your server and only one is mirrored, you stand to lose data because both volumes will be locked out in the event of an issue with the other volume.
What is data replication used for?
Data replication is commonly employed for these reasons:
1. To provide a real time data copy of production data for use in the event that a disaster strikes, or to facilitate regulatory compliance needs by mirroring production data into an off-site environment such as cloud storage.
2. To provide increased application availability and faster recovery times than are possible with traditional backup methods by using continuous data protection technologies that enable rapid failover from primary storage to replicated remote copies.
3. Increasing business continuity and throughput while maintaining performance levels by spreading load across two or more systems or networks using virtualization technologies like VMware vSphere Replication (powered by Veeam). In other words, you’re providing your staff access to critical resources when connectivity is impaired, due to natural or man-made disasters.
Restore Data using Data Replication (Disaster Recovery)
Data replication technology provides a way to recover data from certain events, such as the loss or damage of one or more systems that contain all or some of your production data.
1. Client data is restored onto server(s) containing replicated copies of live data.
2. Replicated volumes are mounted on another system within the environment (preferably within the same data center).
3. Any replicated data (regardless of whether it’s active or passive in nature) is cross-checked with its corresponding backup data using a recovery data file to ensure both are consistent and valid.
4. Client application(s) are restarted on the system running live production data, using restored client replicas as a starting point for any required re-initialization/reconfiguration work.
5. Replicated copies of production data are mounted on yet another system within the environment (preferably within the same data center), cleared of stale files/data and made available for use.
What’s the difference between backup and replication?
Data replication differs from data backup in many ways including:
Continuous vs periodic operation requirements
Data replication runs continuously as opposed to backup windows that occur on a scheduled basis (e.g., nightly) with certain data types. Data replication is typically run continuously and any data that’s modified or created on the production volume(s) being replicated are immediately copied to their corresponding volumes in remote data storage (e.g., cloud-based storage).
Backup, on the other hand, is run at specific times with the goal of capturing data for restoration purposes in the event that it’s needed.
Modifications and changes to live data are typically captured by backup methods as part of their scheduled operations. By comparison, data replication technology employs a “push” technology whereby any changes or modifications made to production data are copied “in real time” to its corresponding remote copy on the same or different platform.
Backup vs Replication – Dehydrated vs Hydrated Data Copies
Data backups need to be reconstructed/hydrated and restored before the data can be used. Unlike data backups, replicated data doesn’t require reconstruction/hydration and can be used immediately if/when required.
Data replication is typically used to replicate entire volumes or file systems, databases and applications; data backups may consist of files or folders, database data files and application files depending on organizational requirements for backup-restore procedures.
Both backup and replication are data protection features. The former is focused at reducing Recovery Point Objectives (RPOs) and preventing data loss. While the latter is built to reduce Recovery Time Objectives (RTOs), ensure business continuity and minimize downtime.
Data backup is a process of storing data in more than one location to ensure that the data can be recovered if necessary.
Data replication involves making copies of all or specific parts of your data so that you have multiple versions of the same thing on hand if something happens with one version.
It’s important to know what these terms mean before trying to implement them because they’re not interchangeable!
We’ll help you figure out which type would best suit your needs by talking through any questions you might have about backups and replication. Have we answered those burning questions? Let us know how we can help protect your company’s valuable information from ransomware attacks, human error, hardware failure, and natural disasters.