Btrfs vs EXT4 - Performance Comparison
In this article you will find out:
- Btrfs vs Ext4 comparison
- how to protect your data
Are you ready? Let's read!
BTRFS and EXT4 are two filesystems for Linux OS with unique features and structures that make them vary from one another. While the Btrfs supports snapshots and built-in RAID support, the EXT4 filesystem is mainly a journaling filesystem that keeps track of all log changes on the filesystem.
Also, the copy-on-write support on the Btrfs is a unique feature that makes the filesystem more interesting to Linux admins. But EXT4 is the most popular Linux filesystem, and it is backward compatible with the older versions. In this article, we will compare these two filesystems in detail.
BTRFS Overview
B-Tree File System (Btrfs) is a relatively new Linux filesystem. Launched in 2009, this filesystem was intended to offer a copy-on-write mechanism and prioritize data integrity, while integrating features for RAID and other advanced actions practiced by Linux system admins. As a modern filesystem, Btrfs also supports fault tolerance and snapshots; it is truly one of the preferred file systems for many Linux users.
Interestingly, the file system is available under the GPL and is open for use for everyone. Also, Btrfs integrates a logical volume manager; it addressed issues regarding checksums and integral multi-device spanning in Linux file systems. With Btrfs, scaling Linux systems is much easier and seamless. Hereunder are how Btrfs features come in handy and make the filesystem stand out among others.
Key Features
- Copy-on-write (CoW): The CoW support implies that when changes are made to a file, only the modified “changes” are written to a new location, while the original data remains as it is.
- Snapshots: If you’re using Btrfs, you can make point-in-time copies of the data saved on your Linux drive(s); this literally means recording snapshots of your stored data. Snapshots can serve as backup copies in data loss scenarios.
- Built-in RAID support: RAID is now, more popular than ever, thanks to the unique features it offers. Btrfs comes with built-in support for RAID levels 0, 1, 10, 5, and 6.
- Subvolumes: A BTRFS subvolume is an integral part of the filesystem that has its own independent file/directory hierarchy and inode number namespace (example: a snapshot).
- Data integrity checks: BTRS supports data integrity checks using checksums for the original data and metadata to ensure there are no data errors.
- Self-healing: Btrfs supports self-healing, which helps it to fix corrupt data automatically without the user running any disk repair utility.
Btrfs Performance
In terms of performance, Btrfs doesn’t offer the best speeds you may seek, but it is decently fast, especially for small data transfers. When writing large data, Btrfs may be relatively slow due to the CoW mechanism. Also, in benchmark tests using the Phoronix Test Suite, BTRFS showed lower read and write speeds compared to EXT4 – with higher latency.
Ext4 Overview
Fourth Extended File System, EXT4, is a newer journaling filesystem version that replaced its predecessor, EXT3. It is inarguably the most used Linux filesystem; it is even the default filesystem for most Linux distros. Ext4 is remarkable for its unwavering stability and outstanding performance. Of course, it comes with some impressive features, including metadata and checksums.
Following the name, Ext4 is an extent-based filesystem used to identify long, contiguous files in single inode pointers. It uses a delayed allocation mechanism to mitigate file corruption and data loss; this delayed allocation allows the filesystem to collect new data that is to be written to a volume before even allocating space for it.
Also, as a journaling file system, Ext4 keeps a log of all changes to the filesystem, which comes in handy for data recovery. This filesystem can store single files of up to 16 terabytes in size, thanks to the delayed allocation technique.
Features of EXT4
- Journaling: “Journaling” in EXT4 allows the filesystem to capture data changes and record them in logs (journals) before the changes are effected on the storage device. This is to mitigate potential file corruption in a case of system crash or power failure.
- Extents: This feature represents a set of contiguous blocks in a file. Ext4 extents reduces fragmentations and improves performance for large-file data transfers. A single Ext4 extent can map up to 128 MiB of contiguous space with a 4 KiB block size.
- Backward Compatibility with Ext3: Ext4 is backward-compatible with Ext3 and even Ext2. This means you can mount Ext2 and Ext3 as Ext4. However, if you want to mount EXT4 as EXT3, you need to disable the new features added on Ext4, which are: ^flex_bg, ^extent, ^uninit_bg, ^huge_file, ^extra_isize, and ^dir_nlink.
- Improved Large File Support: EXT4 can store individual files up to 6.6 Terabytes (TB) and volumes of up to 1 Exbibyte (EiB). It is the most reliable Linux filesystem with such large file support.
- Delayed Allocation: This is a performance improvement technique that works by delaying new block allocation until data is flushed to disk. This helps to reduce the risks of fragmentation that may occur by writing very large data immediately.
Ext4 Performance
Talking of performance, Ext4 does deliver what you would call the best performance for a Linux filesystem. It is inarguably faster than Btrfs for all kinds of tasks, and also as shown in benchmark results. The filesystem is well-optimized for daily workloads, and it is stable. Also, EXT4 performs smoothly for server operations. The major disadvantage of this filesystem is that it lacks support for RAID snapshots.
Btrfs vs. Ext4: What Are the Differences?
The main difference can be pointed to their various mechanisms; one uses Copy-on-Write and the other uses Journaling. In between, one supports RAID snapshots and the other doesn’t. Looking at the detailed overview provided above for these Linux filesystems, it is quite clear to figure out the differences. However, below are the unique differences between these filesystems.
1. Feature Set
Apparently, Btrfs has more modern features to offer than the Ext4; this includes support for RAID levels and snapshots. The subvolume feature on Btrfs is also a big deal, plus, the filesystem supports self-healing. Ext4, on the other hand, is backward compatible, supports journaling, and can store very large files or volumes.
2. Performance Metrics
The Ext4 performs better than Btrfs in everyday tasks. But, the CoW feature of Btrfs gives it a slight edge in handling large-volume files. Also, benchmark results show that Ext4 is a much better filesystem in terms of performance than Btrfs.
3. Scalability
Btrfs was introduced to solve scalability issues with Linux OS. It offers quite many advanced features that make Linux scaling seamless and easy. The Ext4 lacks the appropriate features needed to scale Linux seamlessly.
4. Ease of Use and Management
Both the Ext4 and Btrfs are quite easy to use and manage, even though they vary in many aspects. But, Ext4 is supported by more applications and services than Btrfs.
5. Reliability and Stability
Ext4 is popularly remarkable as a stable filesystem; it proves to be more stable and reliable than all other Linux file systems, and that includes the Btrfs.
When it comes to choosing a file system for your Linux setup, Btrfs and Ext4 are two prominent options that cater to different needs and use cases. Understanding the differences between these file systems can help you make an informed decision based on your specific requirements.
Why Go with Btrfs File System?
Btrfs, or B-tree File System, is designed with advanced features that make it suitable for modern storage needs. Here are some reasons to consider Btrfs:
Data Integrity: Btrfs includes built-in mechanisms for detecting and correcting data corruption, ensuring high data integrity. It uses checksums for data and metadata, which helps in identifying and repairing corrupted files.
Snapshots and Cloning: One of the standout features of Btrfs is its support for snapshots and clones. Snapshots allow you to capture the state of the file system at a specific point in time, making it easy to revert to previous states or create backups. Cloning enables efficient copying of files or directories without duplicating the actual data.
Scalability: Btrfs is highly scalable, supporting large volumes and a significant number of files. It can handle massive storage setups, making it ideal for enterprise environments and large-scale applications.
Dynamic Subvolumes: Btrfs allows the creation of subvolumes, which are separate file system instances within a single partition. This provides flexibility in managing different types of data and can help in organizing storage more effectively.
Built-in RAID Support: Btrfs comes with integrated support for various RAID configurations (RAID 0, 1, 5, 6, 10), offering redundancy and performance improvements without the need for external tools.
Online Defragmentation and Balancing: Btrfs supports online defragmentation and balancing of data across disks, which helps in maintaining optimal performance and efficient storage utilization.
Why Go with Ext4 File System?
Ext4, or Fourth Extended File System, is an evolution of the Ext3 file system and is known for its robustness and reliability. Here are some reasons to opt for Ext4:
Stability and Maturity: Ext4 is a tried and tested file system that has been in use for many years. Its stability and reliability are well-proven, making it a safe choice for critical applications.
Performance: Ext4 is optimized for performance, providing fast read and write operations. It is particularly efficient for small to medium-sized files, making it suitable for a wide range of use cases.
Compatibility: Ext4 is widely supported across various Linux distributions and is often the default file system in many of them. Its compatibility and ease of use make it a hassle-free option for most users.
Efficient Space Allocation: Ext4 uses techniques like extent-based storage and delayed allocation to minimize fragmentation and improve disk space utilization. This helps in maintaining consistent performance over time.
Backward Compatibility: Ext4 offers backward compatibility with Ext3 and Ext2 file systems, allowing for easy upgrades without data loss. This makes it a practical choice for users looking to migrate from older file systems.
Support for Large Files and Volumes: Ext4 can handle large files (up to 16TB) and volumes (up to 1EB), making it suitable for modern storage requirements.
Comaprison Chart for Btrfs vs. EXT4
Filesystem | Btrfs | Ext4 |
Type | Copy-on-Write | Journaling |
File-System Compression | Supported | Not Supported |
Data Integrity | Checksums | Not Supported |
Maximum Number of Files | ~18 quintillions (2^64) | ~4 Billion (2^32) |
Maximum Partition Size and File Size | File Size: 16TiB Partition Size: 16EiB | File Size: 16TiB Partition Size: 1EiB |
RAID Support | Yes | No |
Scalability | Supported | Not Supported |
Performance | Decent | High |
Snapshots | Yes | No |
Ease of Use | Advanced Users | Anybody can use it |
Backward Compatibility | No | Yes |
Self-Healing | Yes | No |
Stability | Medium | High |
Btrfs vs. EXT4 Benchmark
When comparing file systems, benchmarking provides valuable insights into their performance characteristics under various workloads. Both Btrfs and Ext4 have distinct strengths and weaknesses, and understanding their benchmarks can help in choosing the right file system for your needs.
Btrfs vs. EXT4 Speed
Speed is a critical factor in file system performance, affecting read and write operations. Here's a comparison of Btrfs and Ext4 in terms of speed:
Read/Write Speed:
- Ext4: Ext4 generally offers faster read and write speeds, especially for small to medium-sized files. Its mature and optimized codebase allows for efficient handling of file operations.
- Btrfs: Btrfs may exhibit slower write speeds due to its advanced features like checksumming and copy-on-write. However, read speeds can be competitive with Ext4, particularly when leveraging its snapshot capabilities.
Latency:
- Ext4: Ext4 has lower latency for common file operations, making it suitable for environments where quick response times are essential.
- Btrfs: The additional overhead of data integrity checks can introduce higher latency, but this trade-off may be acceptable for users prioritizing data integrity over speed.
Btrfs vs. EXT4 SSD Performance
The performance of Btrfs and Ext4 on SSDs is influenced by their design and optimization for solid-state drives:
Wear Leveling and TRIM Support:
- Ext4: Ext4 supports TRIM operations, which help maintain SSD performance by allowing the drive to manage free space more efficiently. This results in better longevity and sustained performance.
- Btrfs: Btrfs also supports TRIM, but its copy-on-write mechanism can lead to higher write amplification, which may affect the lifespan of SSDs. However, Btrfs's features like snapshots and subvolumes can provide significant benefits for SSD usage.
Performance Consistency:
- Ext4: Ext4's straightforward design often results in consistent performance across different workloads, making it a reliable choice for SSDs.
- Btrfs: Btrfs can exhibit variability in performance due to its complex features, but it can offer advantages in specific scenarios, such as with large file operations or advanced storage management tasks.
Btrfs vs. EXT4 for NAS
Network-Attached Storage (NAS) devices benefit from file systems that offer reliability, performance, and advanced features:
Data Integrity and Protection:
- Ext4: While Ext4 is reliable, it lacks built-in data integrity features like checksumming and error correction.
- Btrfs: Btrfs excels in providing data integrity with its checksumming and self-healing capabilities, making it a strong contender for NAS environments where data protection is paramount.
Snapshots and Backups:
- Ext4: Ext4 does not natively support snapshots, requiring additional software for backup solutions.
- Btrfs: Btrfs's native support for snapshots allows for efficient and quick backups, which is advantageous for NAS devices.
Btrfs vs. EXT4 on Synology NAS Device
Synology NAS devices are popular for home and small business storage solutions, and the choice between Btrfs and Ext4 can significantly impact their performance and capabilities:
Ease of Use and Management:
- Ext4: Synology's DSM (DiskStation Manager) provides robust support for Ext4, with easy setup and management options. Ext4's simplicity and reliability make it a convenient choice for most users.
- Btrfs: DSM also supports Btrfs, offering features like snapshots, data integrity checks, and efficient storage management. These advanced features can enhance the functionality and reliability of Synology NAS devices.
Performance and Reliability:
- Ext4: Ext4 provides consistent performance with low overhead, making it suitable for general-purpose storage needs on Synology NAS devices.
- Btrfs: While Btrfs may have slightly higher overhead, its benefits in data protection and management can outweigh the performance trade-offs, especially in environments where data integrity is crucial.
Protect your data!
Although the arrays are well protected, there is still a risk of data loss. And if this happens to you, then download and install the DiskInternals RAID Recovery application and solve the problem as soon as possible. Successful data recovery of any format is guaranteed by more than 90% thanks to many years of experience in this area. The app will easily recover RAID 0, RAID 1, 0 + 1, 1 + 0, 1E, RAID 4, RAID 5, 50, 5EE, 5R, RAID 6, RAID 60 and even JBOD.
Virtual disks can be mounted to local disks, and all Windows restrictions are easily bypassed — no problem. No special technical skills are required to recover damaged RAID arrays using RAID Recovery; The recovery wizard will help and advise you on everything.
You can also apply the recovery instructions to be completely confident in yourself and the result. To recover RAID data:
- Once the app opens, it will automatically recognize the array and other key indicators.
- Select the desired RAID and scan mode (full or shallow).
- Then wait for the results and preview them for free.
- Finally, purchase a license and export the data to another source of information.
Conclusion
There are multiple Linux filesystems, but these two are the most used, thanks to their capabilities and features. Apparently, these file systems differ in many regards, but they can be used interchangeably; for example, if you were running Ext4 and wish to migrate to RAID storage, you can make a switch from Ext4 to Btrfs. Before choosing between any of these filesystems, you must, first, analyze your needs and go for the one that suits you best.
FAQ
Should I use ext4 or Btrfs?
In summary, Ext4 is an older, reliable file system that is stable but lacks some of the newer features and performance enhancements. Btrfs, on the other hand, offers modern features and is well-suited for contemporary hardware and Linux distributions. For specialized enterprise installations, ZFS remains a top choice due to its advanced capabilities.
Is Btrfs better than ext4 for NAS?
Ext4 offers features like online defragmentation, quota management, and journaling, which Btrfs does not. However, Btrfs provides capabilities not supported by Ext4, such as snapshots, compression, encryption, deduplication, RAID, subvolumes, and checksums.
What is the best file system for NAS?
In summary, both Btrfs and Ext4 are solid choices for your NAS, and the decision between them depends on your specific requirements and use case. If you need advanced features like data checksumming, snapshots, and data deduplication, Btrfs might be the better option.
What is the downside of Btrfs?
Btrfs has two main disadvantages: it lacks native support for encryption and has storage limitations compared to ZFS. However, administrators can use third-party encryption solutions for Btrfs as a workaround. Additionally, extra storage space is required for shadow copies.