Linux filesystems: Ext4, Btrfs, XFS, ZFS and more

Linux supports quite a few filesystem types. Your choice of which filesystem to use can play an important role in optimizing performance, reliability and data integrity. Among the more popular filesystems are Ext4, Btrfs, XFS and ZFS. Each is widely used and offers some unique features and benefits. Metadata handling, journaling, and data integrity mechanisms are central factors in determining their suitability for various workloads. 

Ext4

Ext4, the default filesystem for many Linux distributions, balances performance and reliability. First developed in 1992, Ext has slowly evolved into Ext4. Its metadata is efficiently managed using traditional inode structures, ensuring fast file access and directory traversal. Ext4’s journaling mechanism logs metadata changes, enhancing recovery from crashes. However, while Ext4 is highly reliable, its metadata structures lack the advanced features of some of the newer filesystems, such as using check sums for data integrity.

Btrfs

Btrfs, designed for modern workloads, excels in metadata handling and data integrity. It uses a copy-on-write (COW) mechanism for metadata, ensuring that changes are committed atomically. Its journaling-like functionality includes using checksums for both data and metadata, providing superior integrity verification. However, these features come at the cost of performance, particularly in write-intensive workloads, due to the overhead of copy-on-write operations.