Linux-based operating systems are known for their flexibility. Users can customize the operating system to fit a variety of options, greatly extending its usability in many ways. Those versed in Linux operating systems might be familiar with the many file systems available to users. Two of these, Btrfs and EXT4, are popular choices in the Linux operating system space.
There are some very key differences between these file systems, however. They serve similar purposes but the features supported make choosing between the two a difficult choice. If you’re new to Linux operating systems, it might make for a daunting choice. Both are fortunately well-documented and, as such, it makes it easier to pick based on use cases.
Btrfs vs. EXT4: A Side-by-Side Comparison
| Features | Btrfs | EXT4 |
|---|---|---|
| Type of File System | Copy-on-write | Journaling |
| Deduplication? | Yes | No |
| File System Compression? | Yes | No |
| Checksum Support? | Yes | No |
| Snapshots? | Yes | No |
| Maximum Number of Files | 18 quintillion | 4 billion |
| Maximum Partition Size | 16 exbibytes | 16 tebibytes |
| Maximum File Size | 16 exbibytes | 1 exbibyte |
Btrfs vs. EXT4: What’s the Difference?
Btrfs is a more modern file system, introduced in 2007. EXT4 has been the Linux default since 2006, following the previous EXT3. Btrfs lacks maturity and stability at the time of this writing but is more feature-rich compared to EXT4. EXT4 lacks more robust features but is stable and well-supported on all Linux operating systems.
Btrfs was created with the express purpose of speeding up repair and administration. EXT4 is more of a general filesystem, meant to function for users and administrators alike. Linux operating systems have a long operational history of utilizing EXT-based file systems, dating back to the original introduction of Minix and EXT2 in the 1990s.
Btrfs vs. EXT4: Must-Know Facts
Btrfs
- Supports checksums for file verification
- Utilizes B-trees for efficient storage and processing of files
- Supports massive file sizes
- File system compression natively supported
- Can take file system snapshots
EXT4
- Mature and stable file system
- Not as efficient as Btrfs but well supported
- Utilizes journaling for file storage and processing
- Highly reliable
- Trusted for decades as the standard file system for Linux operating systems
Btrfs vs. EXT4: In-Depth Comparison
When you’re considering a file system for a Linux operating system install, it depends on the intended use of the install. If you are running something at home, for example, a NAS, Btrfs poses multiple benefits. If you’re doing installations for an enterprise environment, EXT4 is the only real choice to make. There is a multitude of reasons for this, so let’s go over the history and facts surrounding both file systems.
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Btrfs
Btrfs was introduced in 2007. On paper, it supports a lot of modern features which may appeal to administrative and business personnel. Native support for RAID arrays is present, which is a boon for file integrity and data redundancy. Btrfs has a lot to offer for any business or home Linux user.
Btrfs In-Depth
One of the more useful features present in Brtfs is the ability for users to create and store snapshots. Snapshots allow users to create a restore point for the state and location of their files and directories. This is great for developers or in the event of accidental deletion. Creating a snapshot is an instantaneous process, thanks to the utilization of copy-on-write as the core component of the file system.
Massive file sizes are easily supported, making Brtfs future-proof as storage media grows in size. This is helpful in data centers as well for data hoarders. Data integrity is ensured through the usage of CRC32 checksums. EXT4 can use external utilities to leverage this, but native support is unique to Btrfs. Solid state drives have improved support through the file system, and have unique detection modes to fully take advantage of the faster storage media.
Where Btrfs falls short is in its lack of stability and being prone to fragmentation. While it is over a decade old, it still isn’t quite as reliable as EXT4. It hasn’t served as the primary file system for default operating system installations, but its reliability is improving with each subsequent release. For those using Linux operating systems on servers meant to provision multiple clients, it probably isn’t an ideal choice.
However, if you’re looking for an alternative to the usual suspects in Linux, it makes a great choice. It is a highly flexible system that supports rapid file transfers and only will get better with further maturation and development.
EXT4
EXT4 has a long history with Linux operating systems. It finds its origin in Minix, a 1987 file system developed by Andrew Tanenbaum. Early builds of the Linux operating system used Minix as the primary file system. 1993 saw the release of EXT2 and it has been the standard file system ever since. EXT4 builds upon EXT3, improving efficiency and file sizes.
EXT4 is a stable and reliable file system and sees constant use in Linux operating systems around the world. In stark contrast with Btrfs, EXT4 uses journaling in place of copy-on-write. They are similar in functionality, but there are some key differences.
EXT4 In-Depth
As the ubiquitous file system of Linux operating systems of all stripes, EXT4 has a lot that makes it attractive. The core of EXT4 uses journaling, or the storage of metadata, before it is written to the disk. This has some bonuses for speeding up the access and writing of files but can lead to data corruption if the metadata doesn’t update in line with what’s on the storage.
Fragmentation is less of a concern in EXT4, thanks in part to its use of multiblock allocation. This feature of the file system means multiple free blocks are sought when writing a file.
An unlimited amount of subdirectories are supported, as EXT4 supports the HTree data structure for file storage and access. It is a close relative to the B-tree seen in use by Btrfs. Checksums are also present in EXT4, but not to the same extent as Btrfs. It uses CRC32 much like Btrfs but needs some setup to provide checksums for files.
The shortcomings of EXT4 regard data recovery and maximum volume size. Corrupted data or directories cannot be detected or recovered by EXT4 natively. If it was corrupted and written on the disk, it is effectively nonexistent in the file system.
The maximum volume size for EXT4 is capped at a maximum of 1 exbibyte, but the file system can only address volumes of around 100 tebibytes without a severe drop in performance and throughput.
Btrfs vs. EXT4: Which One is Better? Which One Should You Use?
When considering a file system, think of what the intended use is going to be. Servers and enterprise-level machines require a different set of needs than a home NAS.
If reliability and stability are your utmost concern, then you want something proven. There are few file systems with the maturity and proven track record of EXT4. EXT4 is a proven and solid file system and has run as the backbone for countless installs of Linux operating systems for decades. It has been a defacto choice for good reason, and any issues that may arise often have solutions. Part of this is down to its extensive history in the Linux community, as it is one of the supported file systems used for business-oriented distros.
If you’re looking for something where file integrity and flexibility are important, Btrfs is a great choice. It doesn’t have the track record of stable performance that EXT4 possesses, but it is still a solid file system. Native support for RAID arrays, snapshots, and checking file integrity via checksums make it a great choice for those who are manipulating and moving a lot of data. It is especially well suited for file servers and network access storage. It doesn’t have as much widespread support in the business sector, but the EXT family of file systems has nearly 15 years of usage as a head start.
For home users, it really comes down to a coin flip. EXT4 is stable and perfectly fine for all use cases. But, if you value being able to take advantage of more advanced features in a file system, then Btrfs might be the choice to make.
There isn’t a necessarily better choice. EXT4 is a legacy file system, and Btrfs represents future developments in the Linux space.
Btrfs vs. EXT4: Alternative File Systems for Linux Operating Systems
If Btrfs and EXT4 aren’t cutting it for you or aren’t supported by your choice of distro, there are a few other popular choices for file systems. Here are some alternatives:
- XFS
- ZFS
- Reiser4
XFS
XFS is a file system built to scale and was developed by Silicon Graphics in 1994. It uses journaling, similar to EXT4, using a journal to keep track of changes before writing to disk. XFS is special because it supports massive file systems, with file sizes of up to 8 exabytes supported. The file system has been a solid choice for file servers and data centers since its introduction.
It also recovers from power failure easily, with the journaling system providing file integrity despite sudden loss of power. Applications and processes can also reserve bandwidth, using a feature called guaranteed rate IO. XFS is the default file system for Red Hat Enterprise Linux, CentOS, and Oracle.
ZFS
ZFS is a file system and logical volume manager developed by Sun Microsystems in 2005. It functions both as a volume manager and can administer RAID arrays easily. Part of the core functionality behind ZFS is a concept called data pooling. In computing memory, RAM is often pooled to serve as a resource for everything that needs it. ZFS takes this concept and pools the storage of the file system, allowing for hard drives to be added and counted as logical volumes with minimal setup.
ZFS is a taxing file system, requiring a minimum of 8GB of RAM to work. It works well for NAS users, providing a versatile storage system with data redundancy. This differs from other file systems by not needing to use the Linux Logical Volume Manager to create and maintain partitions.
It isn’t the default file system for any mainstream distros, but if you’re big on data it makes a great alternative to Btrfs despite missing some of what makes the latter a great choice.
Reiser4
Reiser4 is a highly customizable file system. It hasn’t ended up as the default file system for any distro. The file system is able to be extended by plugins and other features. Reiser4 is fully modular, meaning you can use different plugins to manage aspects of the file system. It has the special distinction of being able to be utilized by different operating systems due to its modular nature.
Stability is present, and the most recent revision of Reiser4 is capable of transparent file compression, differing transaction models, and checksums. Reiser4 is fully capable of using journaling and write-anywhere, or some combination thereof. It is more complex than other file systems available for the Linux operating system and as such isn’t recommended for beginners to the ecosystem.
