What is the maximum total filesystem size supported by ext4?

The maximum total filesystem size supported by ext4 is indeed 1EiB (Exbibyte). The ext4 filesystem, which is the fourth extended filesystem used by Linux, has significant improvements over its predecessor ext3, particularly in terms of size capacity and performance.

Each ext4 filesystem can theoretically scale up to 1EiB or 1,048,576 TiB, allowing it to handle vastly larger volumes of data than earlier filesystems. This high capacity is crucial for modern systems that require efficient data management capabilities for large datasets, such as databases, large-scale applications, or storage systems.

The design of ext4 includes features that support very large files and filesystems, including support for larger block sizes, allowing it to manage and retrieve data efficiently even in vast storage spaces. This makes ext4 suitable for both everyday use and high-demand environments, reflecting the evolving needs of data storage in contemporary computing.