E2compr is a modification to the ext2 file system driver in the Linux kernel to support online compression and decompression of files on file system level without any support by user applications. The ext2 or second extended file system is a file system for the Linux kernel. ... In computing, a file system is a method for storing and organizing computer files and the data they contain to make it easy to find and access them. ... The Linux mascot Tux created by Larry Ewing The Linux kernel is a free software Unix-like operating system kernel that was begun by Linus Torvalds in 1991 and subsequently improved with the assistance of developers around the world. ...

What does e2compr do?

E2compr is a small patch against the ext2 filesystem that allows on-the-fly compression and decompression. It compresses only regular files; the administrative data (superblock, inodes, directory files etc.) are not compressed (mainly for safety reasons). Access to compressed blocks is provided for read and write operations. The compression algorithm and cluster size is specified on a per-file basis. Directories can also be marked for compression, in which case every newly created file in the directory will be automatically compressed with the same cluster size and the same algorithm that was specified for the directory. In computer science, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than a more obvious representation would use, through use of specific encoding schemes. ... UNIX file system (UFS) is a file system used by many Unix and Unix-like operating systems. ... In Unix computing, an inode or i-node is a data structure on a file system that stores basic information about a file, directory, or other file system object. ... In computing, a directory, catalog, or folder, is an entity in a file system which contains a group of files and other directories. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... In computing (specifically data transmission and data storage), block size indicates a nominal size, usually expressed in bytes or bits, of a block of data. ... In computer science, data compression or source coding is the process of encoding information using fewer bits, or information units, thanks to specific encoding schemes. ... In file systems, a cluster is a group of disk sectors used in a File Allocation Table (FAT). ...

E2compr is not a new filesystem. It is only a patch to the ext2 filesystem made to support the EXT2_COMPR_FL flag. It does not require you to make a new partition, and will continue to read or write existing ext2 filesystems. You should consider it is only a way for the read and write routines to access files that could have been created by a simple utility similar to gzip or compress. Compressed and uncompressed files will coexist nicely on your ext2 partitions.

References

Sourceforge project page