Single archive file
The user manages one .cfs archive rather than a permanent extracted folder beside the compressed data.
Arqivexa / .cfs file format
Archive format overview
What is a .cfs file? Arqivexa's compressed archive format.
Arqivexa keeps the .cfs extension for compatibility with archives and release components created before the product was renamed from CFS. The extension is a file-format identifier; the product name is Arqivexa.
01A
One user-managed archive
A .cfs file stores a compressed workspace.
Folder-like Explorer view
Arqivexa can project the archive's directory structure into File Explorer so files are visible and can be requested on demand.
Edits persist back
Supported workspace changes can be committed back into the archive so reopening the same .cfs preserves those changes.
02
Compression model
Independent per-file LZMA2 compression.
Not solid compression
The current release compresses files independently rather than compressing the entire archive as one solid stream.
On-demand access
Because file payloads are independently addressable, Arqivexa can supply the requested file rather than unpacking every file first.
Large-file chunks
CFS2 can store streamed large entries in independently checksummed 64 MiB LZMA2 chunks. CFS1 remains supported for compatibility.
03
Editing and optimization
Archive history can grow as files change.
Changed data can be appended
Normal saves can add new file data and manifests while preserving unchanged compressed blocks.
Optimization removes obsolete history
After the mounted workspace is closed, the Optimize operation can create and validate a compact candidate that removes obsolete archive history.
Optimization is transactional
The current workflow validates the compact candidate before replacing the archive and preserves recovery protection across replacement.
Format boundaries
Compression is not encryption.
- No password protection in 0.5.0
- No built-in encryption in 0.5.0
- Keep separate backups
- Use the current supported Arqivexa release to modify archives
NAMEWhy is it still called
Why is it still called .cfs?
Changing a public file extension would break associations, archives, scripts, and compatibility assumptions. Arqivexa therefore keeps .cfs as the format extension while using Arqivexa as the product brand.