What is Data Deduplication? | Key Concepts & Benefits

Data Deduplication, also known as Intelligent Compression or Single-Instance Storage, is a method of reducing storage overhead by eliminating redundant copies of data.

Data Deduplication techniques ensure that on storage media such as discs, flash, tape, etc., only one unique instance of data is kept. A pointer to the unique data copy replaces redundant data blocks.

Data Deduplication therefore closely resembles incremental backup, which transfers just the data that has changed since the last backup.

Here’s all you need to know about Data Deduplication, as well as some key pointers to keep in mind before you start the process.

What is Data Deduplication?

Data Deduplication, or Dedup for short, is a technology that can help lower the cost of storage by reducing the impact of redundant data.

Data Deduplication, when enabled, maximizes free space on a volume by reviewing the data on the volume and looking for duplicated portions.

Duplicated portions of the dataset of a volume are only stored once and (optionally) compacted to save even more space.

You can deduplicate data to reduce redundancy while maintaining Data Integrity and Veracity.

How does Data Deduplication Work?

• Data Division and Fingerprinting:  
  • Data is broken into 4KB blocks across all volumes. Each block gets a unique digital signature called a fingerprint.
• Deduplication Process (Inline and Background): 
  • The Inline Deduplication Engine reviews incoming blocks, creates fingerprints, and stores them in an in-memory hash store.  
  • A lookup in the hash store checks for duplicate fingerprints. If a match is found, the donor block(existing data) is compared with the new block byte-by-byte. If matched, the new block is not written to disk, and only the metadata is updated.  If no match is found in the cache, the donor block is fetched from disk and compared.
• Background Deduplication:  
  • The background engine works in bulk, comparing fingerprints across all data blocks and removing duplicates similarly to the inline process.
• Data Integrity:  
  • Throughout the deduplication process, no data is lost. Only duplicates are removed while maintaining data integrity.

This method also assures that no data is lost during the Deduplication process.

What is the Importance of Deduplicating Data?

• Data Deduplication is crucial because it decreases your storage space requirements, saving you money and reducing the amount of bandwidth used to move data to and from remote storage sites. 
• Data Deduplication can reduce storage requirements by up to 95% in some circumstances, while your specific Deduplication Ratio can be influenced by factors such as the type of data you’re attempting to deduplicate. 
• Even if your storage requirements are decreased by less than 95%, Data Deduplication can save you a lot of money and boost your bandwidth availability significantly.

What are the Data Deduplication Ratios & Key Terms?

A Data Deduplication Ratio is the comparison of the data’s original size and its size after redundancy is removed, as previously stated.

It’s a metric for how effective the Deduplication procedure is.

Given that much of the redundancy has already been eliminated, the Deduplication procedure produces comparatively poorer outcomes as the Deduplication ratio rises.

A 500:1 Deduplication Ratio, for example, is not much better than a 100:1 Deduplication Ratio—in the former, 99.8% of data is deleted, whereas, in the latter, 99% of data is eliminated.

The following factors have the greatest impact on the Deduplication Ratio:

• Data Retention: The longer data is kept, the more likely it is that redundancy will be discovered.
• Data Type: Certain types of files are more prone than others to contain a high level of redundancy.
• Change Rate: If your data changes frequently, your Deduplication Ratio will most likely be lower.
• Location: The broader the scope of your Data Deduplication operations, the more likely duplicates may be discovered. Global deduplication over numerous systems, for example, usually produces a greater ratio than local Deduplication on a single device.

Data Deduplication Use Cases: Where can it be useful? 

General Purpose File Servers

General-purpose File Servers are file servers that are used for a variety of purposes and may hold any of the following sorts of shares:

• Shared by the entire group
• Home folders for users
• Folders for work
• Shares in software development

Since multiple users tend to have many copies or revisions of the same file, general-purpose file servers are a strong choice for Data Deduplication.

Since many binaries remain substantially unchanged from build to build, Data Deduplication benefits software development shares.

Virtual Desktop Infrastructure (VDI) deployments

Virtual Desktop Infrastructure (VDI) Deployments: VDI servers, such as Remote Desktop Services, offer a lightweight way for businesses to supply PCs to their employees.

There are numerous reasons for a company to use such technology:

• Application deployment: You can deploy applications throughout your entire organization rapidly. This is especially useful when dealing with apps that are regularly updated, rarely utilized, or difficult to administer.
• Application consolidation: It eliminates the requirement to update the software on client computers by installing and running them from a group of centrally controlled virtual machines. This option also minimizes the amount of bandwidth necessary to access programs on the network.
• Remote Access: Users can access enterprise programs via remote access from devices such as personal computers, kiosks, low-powered hardware, and operating systems other than Windows.
• Branch office access: VDI deployments can improve the performance of applications for branch office workers who need access to centralized data repositories. Client/server protocols for data-intensive applications aren’t always designed for low-speed connections.

Since the virtual hard discs that drive the remote desktops for users are virtually identical, VDI deployments are excellent candidates for Data Deduplication.

Additionally, Data Deduplication can help with the so-called VDI boot storm, which is when a large number of users sign in to their desktops at the same time to start the day.

Backup Targets 

Virtualized backup apps, for example, are Backup Targets.

Owing to the large duplication between backup snapshots, backup programs like Microsoft Data Protection Manager (DPM) are great candidates for Data Deduplication.

What are the Methods/Types of Data Deduplication Approaches?

Inline Deduplication Vs Post-processing Deduplication

Aspect	Inline Deduplication	Post-Processing Deduplication
Timing	During data write (real-time)	After data is written (scheduled/asynchronous)
Storage Efficiency	Immediate prevents duplicates from being stored	Delayed, duplicates are removed later after data is fully stored
Computational Overhead	Higher during write operations due to real-time processing	Low during writes, higher later during deduplication process
Initial Storage Requirement	Lower, as duplicates are avoided right away	Higher, as all data is stored in full until deduplication occurs
Best Use Case	When storage optimization is critical and must happen immediately	When high write performance is prioritized and storage can be optimized later

Source Deduplication Vs Target Deduplication

Aspect	Source Deduplication	Target Deduplication
Location of Deduplication	At the source (before data transfer)	At the storage destination (after data transfer)
Network Traffic	Reduces network traffic by sending only unique data	No impact on network traffic, all data is sent
Storage Efficiency	Reduces storage needs right from the source	Reduces storage needs only after data is stored
Deduplication Timing	Before data transfer	After data has been transferred
Best For	Scenarios requiring reduced bandwidth usage	Scenarios focusing on storage optimization without worrying about network load

File-level Deduplication Vs Block-level Deduplication

Aspect	File-Level Deduplication	Block-Level Deduplication
Deduplication Method	Compares entire files	Breaks files into smaller blocks and checks each block
Efficiency	Less efficient, especially when parts of a file change	More efficient, reduces storage even when parts of files change
Granularity	Coarse (file-level)	Finer(block-level)
Storage Savings	Lower, only eliminates identical files	Higher, eliminates duplicate blocks within files
Processing Power	Requires less processing	Requires more processing due to block comparisons
Best Use Case	Suitable for environments with few file changes	Ideal for environments with frequent file changes or large datasets

Data Deduplication vs Thin Processing vs Compression: What is the Difference?

Compression is another approach frequently associated with Deduplication.

Data dedup, on the other hand, looks for duplicate data chunks, whereas compression utilizes a method to minimize the number of bits required to represent data. When data comes to Deduplication, Compression, and Delta Differencing are frequently used.

When combined, these three data reduction strategies are intended to maximize storage capacity.

In a storage area network, thin provisioning maximizes capacity use.

Erasure coding, on the other hand, is a Data Protection Strategy that divides data into fragments and encodes each fragment with redundant data to aid in the reconstruction of corrupted data sets.

Deduplication also has the following advantages:

• A smaller data footprint; 
• less bandwidth used while copying data for remote backups, replication, and disaster recovery;
• Longer periods of retention;
• Reduced tape backups and faster recovery time targets

What are the advantages of Data Deduplication?

Backup Capacity

There is far too much redundancy in Backup Data, especially in full backups. Even though incremental backups only back up modified files, some redundant data blocks are invariably included.

That’s when Data Reduction technology like this shines.

Data Deduplication software can help you locate duplicate files and data segments within or between files, or even within a data block, with storage requirements that are an order of magnitude lower than the quantity of data to be saved.

Continuous Data Validation

There is always a risk associated with logical consistency testing in a primary storage system. The block pointers and bitmaps can be corrupted if a software bug causes erroneous data to be written.

If the file system is storing backup data, faults are difficult to identify until the data is recovered, and there may not be enough time to repair errors before the data is recovered.

Higher Data Recovery

The Backup Data Recovery service level is an indicator of a backup solution’s ability to recover data accurately, quickly, and reliably.

Complete Backups and Restore are faster than incremental backups because incremental backups frequently scan the entire database for altered blocks of data, and when recovery is required, one full backup and numerous incremental backups must be used, which slows down recovery.

Backup Data Disaster Recovery

For backup data, Data Deduplication has a good capacity optimization capability; doing a full backup every day requires only a small number of disc increments, and it is the data after capacity optimization that is transmitted remotely over WAN or LAN, resulting in significant network bandwidth savings.

Conclusion

As organizations expand their businesses, managing large volumes of data becomes crucial for achieving the desired efficiency. Data Deduplication powers stakeholders and management to handle their data in the best possible way. In case you want to export data from a source of your choice into your desired Database/destination then Hevo Data is the right choice for you! 

Learn how to handle duplicate data effectively with our comprehensive guide on identification and resolution strategies.

Want to take Hevo for a spin? Try Hevo’s 14-day free trial and experience the feature-rich Hevo suite firsthand. You can also have a look at the unbeatable pricing that will help you choose the right plan for your business needs.

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