In a world where data is king, backups are the knights in shining armor that come to their rescue. But not all backups are created equal. You see, there are different types of backups, each with its own unique set of strengths and weaknesses.
The four most common types of backups are block level, file level, incremental, and differential backups. Each one plays a critical role in safeguarding our valuable data from loss, corruption, or theft. However, each one is different from the other.
In this article, we will explain the differences between each backup type. We will also look at where they are used, why they are important, and which one is right for your particular backup needs.
What is a Block Level Backup
Pros
- Efficient storage utilization through incremental backups.
- Less resource utilization by reading from a snapshot.
- Allows for frequent backups without performance issues.
- Faster upload times.
- Useful for large files and data sets.
Cons
- Recovering a single file can be time-consuming as the backup software checks all blocks of the file, including the initial full backup.
- Data reliability and consistency can be compromised if any block is corrupted or inconsistent, negatively affecting the ability to recover the whole file.
Block level is a sophisticated data backup technique that allows you to back up only the changed parts of the data instead of the entire file. This technology uses snapshots to read data in the same sized blocks as the file system, which are then split into smaller blocks based on the total file size.
The smaller block sizes are different depending on the size of the total file. The table below summarizes the size of these blocks depending on the total size of the file:
Note: These can be different for different block-level backup solutions, but the majority of the software follows these rules.
| Size of the File | Size of the Blocks |
| 1 MB – 512 GB | 128 KB |
| 512 GB – 1024 GB | 256 KB |
| 1024 GB – 1 TB | 512 KB |
A block-level backup software identifies new blocks and differentiates them from old ones using hashes, which are unique codes that represent every block. The software calculates these hashes separately for each block and then compares them to their original value available in the original data source.
If the software detects a mismatch between the available backup value and the data source value, the block in the backup repository is synced with the original data block. This process ensures that only the changed blocks are uploaded, saving both time and bandwidth.
In simpler words, a block-level backup is a kind of incremental backup, where only the blocks containing changed data are replaced.
However, as the number of files and the size of data increases, the block-level backup process requires more storage space and CPU resources for hash calculations. Newly added files, in particular, may require additional storage and resources as the software must calculate and store new hashes.
Use Cases
Block-level backup is a powerful tool for managing and storing data in a variety of applications and use cases. Its ability to provide high performance, reliability, and fault tolerance makes it an essential component in many modern IT infrastructures. Here are some common use cases.
- Virtualization: Block backup is often used in virtualization environments to store virtual machine images and data. This allows for easy management and migration of virtual machines between hosts and data centers.
- Databases: It is well-suited for structured workloads such as databases, including Oracle, MySQL, and NoSQL databases. This is because block storage provides consistent performance and low latency for I/O-intensive applications.
- Email servers: It can be used for email servers such as Microsoft Exchange, as it provides high performance and reliability for storing and retrieving large amounts of email data.
- Fault tolerance and high availability: This backup can be used with RAID (Redundant Array of Independent Disks) to improve fault tolerance, enhance performance, and ensure High Availability (HA). This means that if one disk fails, data can still be accessed and the system remains operational.
What is File Level Backup
Pros
- Ability to backup specific folders or files on a volume.
- Flexible backup policies for different types of data on the same volume.
- Incremental backups save storage space by backing up changed files only.
- Easy to restore individual files without restoring the entire volume.
Cons
- Slower backup and restore times for large amounts of data.
- Not suitable for backing up operating systems.
- Limited support for certain file systems.
File-level backups focus on individual files and folders rather than entire storage volumes or disks. File-level backups are often used for unstructured data, such as documents, media files, and other types of digital content, which can be easily identified and restored in case of data loss. The File History feature in Windows is an excellent example of a file-level backup.
File-level backups work by creating a copy of each file and folder and storing them in a different location, such as an external hard drive, a cloud backup service, or a tape backup system. This ensures that the data remains intact and accessible even if the original storage device fails or becomes corrupted. The backups can then be used for data recovery.
Each file and folder is backed-up as-is, and not in different containers or locations. Some software also can take backups of the same files and folders each time a change is made. This creates a new version of the same file/folder, and the user can store whichever version they want of the same file/folder when needed.
Use Cases
Following are the common use cases where file backup comes in handy.
- Shared Storage: It can be used as shared storage locations for multiple user groups, departments, and teams. This allows different users to access and share files via a Local Area Network (LAN), using a single global namespace that spans multiple scale-out nodes.
- Archiving and Retention: This backup can also be used for data archiving, retention, and compliance purposes. It involves storing files and data over a long period, securely and reliably that meets regulatory requirements.
- Target Storage: File storage is often used as target storage for databases, applications, physical and virtual servers, and backup software. This means that files are stored on file storage systems, rather than on the primary system or device where they were created or used.
- Hybrid Storage: File storage can be used as part of hybrid storage systems, which combine on-premises file storage with cloud file storage. This allows organizations to use a mix of storage options, based on the needs of different data types, such as hot tier data (which requires fast access) and cold and archival data (which can be stored in lower-cost, cloud-based storage solutions).
What is Incremental Backup
Pros
- These are quick since they only back up changes made since the last backup.
- They save storage space as they do not need to back up entire files each time.
- Each backup increment can store a different version of a file or folder.
Cons
- The full restore process is slower compared to other types of backups because it requires the first full backup and all incremental backups since then.
- Finding the correct increment containing the latest version of a specific file or folder is necessary to restore it, which can be time-consuming.
Incremental backups are a smart data backup technique that saves time and storage space by only copying data that has changed since the last backup. This approach starts with a full backup of all data, followed by periodic incremental backups that only capture the changes made since the last backup.
For instance, after a full backup on Tuesday, incremental backups can be scheduled for the following days to capture any changes made to the data. This backup strategy works by comparing the current state of the data to the previous backup and only copying the parts that have been modified.
When restoring data using incremental backups, a complete set of incremental backups and the initial full backup are needed. These incremental backups are bundled together to form a complete backup of the data.
By employing incremental backups, users can save storage space and reduce backup time, while ensuring that they have a complete backup of all data that can be used for restoring purposes. This approach is mostly used when the data volume is too huge to perform complete backups every other day.
Incremental backups save both time and bandwidth as only the changed data needs to be updated.
That said, there are different types of incremental backups, each with its own properties and purposes.
Synthetic Full Backup
A Synthetic Full Backup is a type of Full Backup as well as an Incremental Backup. It is a strategy that allows for the creation of a complete backup without the need to copy and read the data from the source repository. Instead, the system reads the last full backup along with the incremental backups and uses them to create a new full backup.
In traditional backup administration, full backups were conducted during a designated time window, typically at the end of the workday. However, with round-the-clock operations and international business, this backup window has been eliminated, and there may not be enough time to conduct a full backup without disrupting business processes.
Additionally, with the ever-growing size of data stores, conducting a full backup may not be feasible due to the resources required. Synthetic full backup helps to address these challenges by reducing the need for traditional full backups while still providing a complete backup of the data.
By using Synthetic Full Backup, organizations can save time, and resources, and avoid business disruptions, while still ensuring that they have a complete backup of their data. This backup strategy is a smart solution for businesses looking to streamline their backup process while maintaining data integrity.
Enhanced Incremental Backup
In Enhanced Incremental Backup, the system can identify files that have been renamed or moved since the last backup, identify any changes within, and uploads them onto the backup destination. This improves the efficiency of the backup process and reduces the amount of data that needs to be backed up. As a result, the backup process becomes faster and consumes fewer resources.
Enhanced Incremental Backup is a backup strategy that offers additional monitoring functionality to ensure that each backup is comprehensive and up-to-date. This way, it does not need to index the source and the backed-up data to view the differences – it already knows which files have been changed.
In an Enhanced Incremental Backup, any changes made to the original data source are backed up to the backup repository, and the data inside the initial full backup is replaced with the new one.
This type of backup is particularly useful for organizations with significant amounts of data that changes frequently. With Enhanced Incremental Backup, businesses can be confident that their data is being backed up correctly and that they will be able to recover it in the event of a data loss or disaster.
Forever Forward Incremental Backup
A Forever Forward Incremental Backup only requires one initial full backup, followed by subsequent incremental backups that are stored in a centralized backup system. This backup approach significantly reduces the amount of data transferred during backups, making it an efficient and cost-effective option for organizations with large amounts of data.
When data needs to be restored from the backup, the system generates a full backup on-the-fly by combining the initial full backup with the subsequent incremental backups. This process enables organizations to quickly recover data without having to transfer large amounts of data, which can be time-consuming and costly.
To implement this backup strategy, the system breaks data into smaller chunks and stores them in disk or cloud storage. It also creates a point-in-time backup that maps to the data chunks, making it easy to restore data to a specific point in time.
That being said, a Forever Forward Incremental Backup backs up the data only after indexing the source data and the already backed-up data, spots the differences and then continues to copy it.
Reverse Incremental Backup
The Reverse Incremental Backup is a sophisticated approach to backup data that starts with a full backup, followed by incremental backups of only the changes made since the previous backup. But this is where things get complicated.
Unlike other incremental backup methods discussed above, a Reverse Incremental Backup creates an incremental backup and applies it to the original full backup to create a new copy of the full backup. However, the original data inside the original full backup is left behind and retained inside the backup repository in one needs to revert to a specific time.
If things sound confusing, then watching the following video might clear things up:
This ensures that the original full backup is always available and unchanged. Subsequent incremental backups are then prepared by identifying changes compared to the current full backup, and they are used to create another, more up-to-date full backup.
This process guarantees that a complete backup copy is always accessible, enabling users to restore data from previous full backup copies in case of a data loss event. Reverse incremental backup is a reliable and efficient data protection method that provides peace of mind for businesses and organizations.
However, with that said, one downside of the Reverse Incremental Backup is that if one incremental backup is corrupted, it disrupts the chain of the backups, and therefore impacts the whole full backup.
Synthetic Full vs. Enhanced Incremental vs. Forever Incremental vs. Reverse Incremental Backup
The following table highlights the properties of the different types of Incremental Backups:
| Synthetic Full Backup | Enhanced Incremental Backup | Forever Incremental Backup | Reverse Incremental Backup | |
|---|---|---|---|---|
| Backup Method | Full and incremental | Full and incremental | Full and incremental | Full and incremental |
| Number of Full Backups | 1 | 1 | 1 | Multiple |
| Backup Time | Long | Short | Short | Short |
| Restoration Time | Long | Short | Short | Short |
| Risk of Data Loss | Low | Low | High | Low |
| Efficiency | Low | High | High | High |
Use Cases
Incremental backup is extremely useful for various organizations. Here are its major use cases.
- Efficient Backup Strategy: These are ideal for organizations with large data sets and limited backup windows. They are also useful for businesses with frequent changes to their data.
- Cost-effective Solution: They save storage space by only backing up changes to the data, which is cost-effective compared to full backups.
- Disaster Recovery and Business Continuity: Incremental backups provide a reliable backup of data in case of a disaster, such as data loss or ransomware attacks. They help businesses maintain continuity by ensuring that data is available even during downtime.
- Fast Backup and Recovery: They are the fastest backup method since they only backup increments. They also enable quick recovery times for individual files and folders.
- Flexible Data Recovery: These backups allow for flexible data recovery, as each backup increment can store a different version of a file or folder. This enables businesses to restore data to specific points in time.
What Is Differential Backup
Pros
- Faster restoration compared to incremental backup.
- Backing up data using differential backup is faster than performing a full backup.
- Storage space requirements for differential backup are lower than those for a full backup.
Cons
- Takes longer to restore data compared to a full backup.
- Backing up data using differential backup is slower than incremental backup.
- Storage space requirements for differential backup are higher than those for incremental backup.
Differential backups provide a balance between full backups and incremental backups. Full backups copy all data to a backup location, which requires significant time and bandwidth. Incremental backups, on the other hand, only back up changed data since the last backup. However, it can take longer to recover all the data from an incremental backup since multiple backups need to be compiled and restored.
A differential Backup functions by taking a unique approach in backing up only the files that have changed since the last full backup. For instance, let’s suppose a full backup is done on Sunday. On Monday, a differential backup is performed, capturing only the altered files since Sunday’s full backup.
Similarly, on Tuesday, another differential backup is done, capturing the files that have changed since Sunday’s full backup, including any changes made on Monday and Tuesday. This process continues until the next full backup is carried out.
These backups can be a smart option for organizations that aim to strike a balance between backup speed, storage space, and recovery time. Although differential backups may require more storage space than incremental backups, they consume less time to recover data than full backups.
Note: Since each differential backup comprises all modifications made since the last full backup, it can offer a more comprehensive backup of all data than incremental backups.
Use Cases
Following are the common use cases where differential backups play a vital role.
- Balancing backup speed and storage space: These are suitable for organizations looking to balance backup speed, storage space, and recovery time. They offer a middle ground between full and incremental backups by backing up only the files that have changed since the last full backup. This approach can provide more comprehensive backups of all data while reducing backup time and storage space requirements.
- Hybrid backup strategy: This strategy combines full and differential backups and can provide an optimal balance of storage space and speed. It typically involves performing a full backup over a weekend, followed by differential backups scheduled throughout the week. The initial full backup may take longer to complete, but the subsequent differential backups are faster and require less storage space.
- Time management: These backups can be useful in managing backup windows and optimizing backup time. As the file size of each differential backup grows with time, it can impact backup time towards the end of the week, potentially exceeding the backup window. Understanding the backup window and scheduling backups accordingly can help manage backup time and ensure that the backups are completed within the allocated time frame.
How to Create Full, Incremental, or Differential Backups
There are many different tools available that can be used to perform all sorts of backups. One such software is the MiniTool ShadowMaker.
MiniTool ShadowMaker is an excellent option for creating block-level backups. This backup software provides three backup modes: full backup, incremental backup, and differential backup. The default mode for MiniTool ShadowMaker is an incremental backup, which efficiently utilizes storage space.
If you want to backup files using MiniTool ShadowMaker, follow these steps as an example:
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Download MiniTool ShadowMaker.
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Launch the software and navigate to the Backup page.
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On the Backup page, you can choose the source of the backup and the location where you want to save it.
To choose the source, click on “SOURCE” and select the folders and files you want to back up from options like User, Computer, and Libraries.
To choose the destination, go to “DESTINATION” and select a location that can be either local or remote.
MiniTool ShadowMaker Backup page -
If you want to change the backup type to manage disk space, click on “Options,” select “Backup Scheme,” and turn on this feature manually. You can then choose between Full, Incremental, and Differential backup modes.
Choose the backup type If you want to create an automatic backup, click on “Options,” select “Schedule Settings,” and turn on this feature. You can then set the backup to occur at a specific time daily, weekly, monthly, or during an event.
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Lastly, click on “Back Up Now” to begin the backup process.
Conclusion
The choice between block level, file level, incremental, and differential backups ultimately comes down to the specific needs and constraints of your organization. Each type of backup has its own advantages and disadvantages, and the best backup strategy will depend on factors such as data size, frequency of changes, available storage space, and recovery time objectives.
Understanding the differences between these backup methods can help you make an informed decision and create a comprehensive backup plan that meets your unique requirements. Remember, a backup strategy is not a one-size-fits-all solution.
It is important to regularly review and update your backup plan to ensure that your data remains protected and your recovery processes remain effective. With the right backup strategy in place, you can have peace of mind knowing that your data is safe and accessible, no matter what challenges may arise.
Frequently Asked Questions (FAQs)
What is a Full Backup?
What are the 4 types of Incremental Backups?
What is the difference between Enhanced Incremental Backup and Forever Incremental Backup?
Filed under: Infotech | Tagged: Network Admin, Technology Explained |
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