Cromfs 1.5.2

Cromfs is a compressed read-only filesystem for Linux. Cromfs is intended for permanently archiving gigabytes of big files that have a lot of redundancy. It is more aimed at heavy compression than at a light fingerprint.
Version restrictions:
- Filesystem is write-once, read-only. It is not possible to append to a previously-created filesystem, nor it is to mount it read-write.
- Max filesize: 2^64 bytes (16777216 TB), but 256 TB with default settings.
- Max number of files in a directory: 2^30 (smaller if filenames are longer, but still more than 100000 in almost all cases)
- Max number of inodes (all files, dirs etc combined): 2^60, but depends on file sizes
- Max filesystem size: 2^64 bytes (16777216 TB)
- There are no "." and ".." entries in directories.
- mkcromfs is slow. You must be patient.
- The cromfs-driver has a large memory footprint. It is not suitable for very size-constrained systems.
- Ownerships are not saved.
- Maximum filename length: 4095 bytes
Main features:
- Data, inodes, directories and block lists are stored compressed
- Duplicate inodes, files and even duplicate file portions are detected and stored only once
- Especially suitable for gigabyte-class archives of thousands of nearly-identical megabyte-class files.
- Files are stored in solid blocks, meaning that parts of different files are compressed together for effective compression
- Most of inode types recognized by Linux are supported (see comparisons).
- The LZMA compression is used. In the general case, LZMA compresses better than gzip and bzip2.
- As with usual filesystems, the files on a cromfs volume can be accessed in arbitrary order; the waits to open a specific file are small, despite the files being semisolidly archived.