Btrfs vs. ZFS: Leading Linux Filesystems Compared

Hard disk drive

Btrfs vs. ZFS: Leading Linux Filesystems Compared

Key Points:

  • ZFS stands for Zettabyte filesystem. Sun Microsystems originally created it as part of its Solaris operating system.
  • Btrfs stands for B Tree Filesystem, It is often pronounced as “better-FS” or “butter-FS.”
  • ZFS combines a filesystem and volume manager. 
  • Btrfs uses Copy-on-Write (COW), a resource management technique where a copy of original data is held while the source data is modified or updated.

Linux is definitely the thinking person’s operating system and its filesystems are one thing that makes it so intuitive and user-friendly.

There are over 100 open and closed-source Linux-compatible filesystems, which can be used as its primary data storage format and structure and organize data for your use.

ZFS and Btrfs are two well-known filesystems with distinct metadata and features for organizing your files.

In this article, we’ll compare Btrfs and ZFS to examine their features to see which is the better filesystem for today’s Linux user. 

Btrfs vs. ZFS: Full Comparison

Btrfs and ZFS both combine the organization and management of data with additional features that increase data stability and provide an intuitive user experience.

Leading Linux kernel developers, like Theodore Ts’o, have worked on these filesystems to provide functionality and utility that has been absent in Linux filesystems. However, there are significant differences in their specifications, development trajectory, level of commercial support, and applications where they perform best.

Linux is an open-source, Unix-like operating system.


Btrfs vs. ZFS: A Side-by-Side Comparison

What it is Copy-on-write (COW) file system and logical volume manager Journaling file system and volume manager 
Primary UseFilesystem for LinuxFilesystem for Linux
ArchitectureB-treePooled storage
Max Volume Size16 exbibytes (2 64 bytes)256 trillion yobibytes (2 128 bytes)
Max File Size16 exbibytes (2 64 bytes)16 exbibytes (2 64 bytes)
Max File Name Size255 ASCII characters255 ASCII characters
Max Number of Files 264Unlimited
Copy-on-Write (CoW)YesYes
Initial Release 2009June 2006
Influential Developers IBM
Chris Mason
Red Hat
Sun Microsystems
Open FormatYes Yes (OpenZFS)
Technologies InfluencedFedora33, Oracle Linux, SUSE Linux, ReactOS, Fedora WorkstationOpenSolaris, illumos distributions, OpenIndiana, FreeBSD, Mac OS X Server, NetBSD, Linux

Btrfs vs ZFS: 10 Need to Know Facts

  1. ZFS stands for Zettabyte filesystem. Sun Microsystems originally created it as part of its Solaris operating system.
  1. Btrfs stands for B Tree Filesystem, It is often pronounced as “better-FS” or “butter-FS.”
  1. ZFS combines a filesystem and volume manager. 
  1. Btrfs uses Copy-on-Write (COW), a resource management technique where a copy of original data is held while the source data is modified or updated.
  1. ZFS became open-source in 2005 and subsequently closed-source when the Solaris operating system was purchased by Oracle. By this time an open-source version (OpenZFS) has been exported to Linux.
  1. Btrfs was originally developed at Oracle. Chris Mason is the principal author. 
  1. ZFS provides robust data protection using features like end-to-end checksumming to protect against the effects of data corruption or disk failure. 
  1. Btrfs uses metadata mirroring, self-healing, and snapshots to maintain a high level of data integrity. 
  1. ZFS pools and manages the data from multiple physical disks as a unified storage pool. It then organizes and presents the storage pool as a virtual device (vdev).
  1. Both Btrfs and ZFS support character file names of only 255 characters.

What is Btrfs?

Btrfs is one of the most modern filesystems available for Linux and uses a copy-on-write B-tree system architecture.

Several commercial partners have intentionally developed it to deliver valuable features like pooling, snapshots, and checksums, which may not be present in other filesystems. It also offers a high level of data stability and protection, with a clean, user-friendly interface, making it suitable for enterprise applications.

The History of Btrfs

Btrfs was written by a software engineer from Oracle, Chris Mason. It addresses a recognized weakness in the ext4 filesystem and aimed to move Linux file system technology forward, rather than enhance an existing filesystem. 

The 1.0 version of Btrfs was completed in late 2008 and finally accepted by the Linux kernel in 2009 and offered as an experimental root file system by several Linux distributions. By 2011, some of Btrfs’ features has been integrated with the Linux kernel mainline. Other developers like Miao Xie at Fujitsu had become involved and contributed enhancements. A year later Oracle Linux and SUSE Linux Enterprise transitioned Btrfs from an experimental to a supported filesystem, followed by other leading Linux distributors like RedHat, Fedora, and Synology. 

Dell PowerEdge 2950
Btrfs and ZFS are both trusted filesystems for Linux.

©Roman Samborskyi/Shutterstock.com

Key Features of Btrfs

Btrfs has several features and benefits that make it an ideal filesystem for contemporary enterprise applications. 

Metadata Mirroring

Btrfs mirrors its metadata, storing two copies per volume. Mirroring helps to preserve the integrity of essential metadata like filenames, folder structures, locations, and access permissions. This means that the data can be recovered if there is corruption or damage to the hard drive.  

Self-Healing of Files

Legacy filesystems can be vulnerable to fault tolerance, with errors going unnoticed that cause widespread data corruption.

Btfs prevents such errors by checksumming both the data and metadata, verifying the checksums with every read process. Any mismatches or broken data can be remedied using mirrored metadata and Redundant Array of Inexpensive Disk (RAID) volumes.  

Snapshots and Frequent Backups

Btrfs uses sequential system snapshots to copy entire folders at a single point in time. If data is lost and corrupted, Btrfs can use the cache of snapshots to rapidly restore the data to the point of the most recent snapshot. You can also: 

  • Schedule system backups with point-in-time copies generated as frequently as every five minutes
  • Customize up to 256 hourly, daily, or weekly recovery points
  • Directly review earlier versions of files and restore them manually

Efficient Drive Storage

Unlike many competitors of Linux filesystems, Btrfs does not require large amounts of additional Drive storage space for file versioning and history data, making more storage space available for your actual data.

Convert Utility for Other Linux Filesystems

Btrfs supports the conversion of ext2, ext3, or ext4 filesystems to Btrfs. Use the Btrfs-convert utility to convert the root file system or individual files and folders to Btrfs. Btrfs routinely protects the original data with a snapshot that allows the conversion to be rolled back if necessary.

What is ZFS?

ZFS is a Linux filesystem and volume manager that is available in both open-source and commercial versions. OpenZFS is the open-source version and Oracale, Inc. acquired the closed version with the purchase of the Solaris operating system from Sun Microsystems. 

ZFS is a volume manager and a file system and can pool and manage the data from multiple physical volume block storage devices like hard drives and memory cards. The Zpool function organizes the data so that an OS can efficiently use it along with managing the stored data and files. In addition, ZFS has state-of-the-art data protection with the use of snapshots and RAID to preserve data integrity.

OpenZFS logo
ZFS was created for storage systems in servers and workstations.

©https://commons.wikimedia.org/ – License

The History of ZFS

ZFS was first released as part of Sun Microsystem’s Solaris OS in 2001. It became open-source in 2005 when the Solaris OS was released under an open-source license.

While it was open-source, ZFS was ported to other OS, including Linux and macOS, where it became known as OpenZFS. However, when Oracle Inc. acquired Sun Microsystems it became closed source. OpenZFS has continued with ongoing development and support from the Linux community.

Features of ZFS

ZFS is also a powerful, modern filesystem that is equipped with features and functionality that make it suitable for enterprise-level applications and server use.

The main features of ZFS include: 

Size and Capacity

ZFS provides 16 exbibytes (264 bytes) file sizes and can accommodate almost infinite scaling of its data store with no loss of integrity. 

Volume Management

ZFS pools, organizes, and manages the data from a range of physical storage types. It can complete a variety of volume-related tasks, including managing tiered storage and caches.

ZFS also provides data compression and deduplication, taking pressure off the system RAM.

High Read/Write Efficiency

ZFS’s advanced volume management enables it to write to areas of the filesystem (vdevs) that have the most space available. By writing across all the vdevs in the Zpool, ZFS efficiently manages the entire pool for maximum performance.

Data Integrity

ZFS protects the integrity of its data in several ways. It undertakes routine hierarchical checksumming and frequent snapshots with automatic rollback to the most recent changes if the system data becomes corrupted. It also has a proprietary form of RAID, known as RAID-Z, that strips the system disks in a targeted and efficient way.   

Products That Use Linux Filesystems

Btrfs and ZFS are advanced Linux Filesystems that offer data integrity, deduplication, protection, compression, encryption, and more features. Here are devices that use Linux:

  • Servers: Btrfs and ZFS are good for use in servers that need to store large amounts of data.
  • Desktops: These filesystems can also be used on desktops to store information.
  • NAS devices: Linux filesystems are common on NAS devices, such as those created by Synology and QNAP.

Btrfs vs. ZFS: Which One is Better? Which One Should You Use?

Btrfs and ZFS are comparable COW filesystems that deliver high-utility data management for both personal computing and enterprise applications. They are the leading choices for Linux filesystems that provide system snapshots and other robust forms of data protection.

Btrfs has a slight advantage because it has been directly integrated into the kernel. However, the scalable and flexible nature of ZFS, along with its almost dogged data protection, has given it the edge over its competitors.

Up Next

Frequently Asked Questions

What is RAID?

RAID stands for Redundant Array of Inexpensive Disks. RAID is a data storage virtualization technology that combines multiple disk drives into usable organized units for improved efficiency and performance.

There are several numbered RAID levels that refer to how data is distributed across the participating drives and the level of redundancy or performance delivered. The higher the RAID level, the greater the data security and performance enhancement.

What are the basic functions of a filesystem?

Here is a quick list of the basic functions of a filesystem:

  1. Non-volatile data storage and organization
  2. Provision of a namespace: a system of naming and organizing the constituent files and data
  3. Provision of a metadata structure to support the namespace with hierarchy and directory structure, carrying supplementary information, like file date, size, or location
  4. Use of an Application Programming Interface (API) so that files and directories can be created, accessed, moved, or deleted by the user
  5. Data security and protection from silent corruption and malicious attacks along with access control

What are the main Linux directories?

The directories of the Linux operating system have a tree architecture that is standardized by the Linux Filesystem Hierarchy Standard (FHS). The main directories Linux uses include:


  • / (root filesystem) – This is the top-level directory and contains all the files for booting Linux
  • /bin – This directory contains user-executable files
  • /dev – Device files for any connected hardware devices (not drivers)
  • /home – The location of user files, with subdirectories for each user
  • /lib – Shared library files that are essential for the system boot
  • /media – A directory for external removable storage and drives like USB thumb drives

What are some other Linux filesystems?

Other examples of Linux filesystems include: 

What is deduplication?

Filesystems use data deduplication to reduce duplicate copies of data that take up storage space. Eliminating this unnecessary data improves storage utilization and expense. Data is deduplicated by comparison of byte patterns which are contiguous blocks of data. If data duplications are found, the redundant data is deleted and replaced with a reference.

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