Compression Extension
e2compr is a modification to the ext2 driver in the Linux kernel to support compression and decompression of files by the file system, without any support by user applications. e2compr is a small patch against ext2.
e2compr 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.
e2compr is not a new file system. It is only a patch to ext2 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 file systems. One can consider it as simply 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 coexist nicely on ext2 partitions.
The latest e2compr-branch is available for current releases of Linux 2.4, 2.6, and 3.0. The latest patch for Linux 3.0 was released in August 2011 and provides multicore and himem support. There are also branches for Linux 2.0 and 2.2.
Read more about this topic: Ext2
Famous quotes containing the words compression and/or extension:
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—Samuel Beckett (1906–1989)
“‘Tis the perception of the beautiful,
A fine extension of the faculties,
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Without which life would be extremely dull.”
—George Gordon Noel Byron (1788–1824)