Independent files
Each file is compressed independently in the current format rather than depending on one continuous compression dictionary across every archive member.
Guides / Compression
LZMA2 archive storage
LZMA2 compressed archives designed for editable file access.
Arqivexa 0.5 stores file payloads in its .cfs format using independent per-file LZMA2 compression. That differs from a single solid compressed stream across the entire archive and supports Arqivexa's file-oriented editing model.
01
Compression model
Per-file compression instead of one solid stream.
File-oriented access
When a projected file is requested, Arqivexa can locate the relevant file data without needing to conceptually rebuild an entire solid stream just to access one member.
Editing tradeoff
Independent compression can sacrifice some of the ratio advantages that solid compression may achieve across many similar files, but it fits an archive intended to support independent file access and change.
02
Chunking
Large files are divided into independently checked chunks.
The current CFS2 archive design uses chunks up to 64 MiB for file data. Chunking provides bounded units for storage and integrity checking while preserving the per-file organization of the archive.
Checksummed data
Archive data includes integrity information so Arqivexa can validate stored content rather than treating compressed bytes as unchecked opaque blobs.
Manifest metadata
The archive maintains metadata describing files and their stored data so the projected directory can be reconstructed when the archive is reopened.
Optimization
Editing can leave obsolete historical data in the archive. After closing the workspace, Optimize can transactionally rewrite the archive to remove no-longer-needed history.
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Search terminology
LZMA2 archive, LZMA2 compression and Windows compressed files.
Searches for LZMA2 archive, LZMA2 compressed files, LZMA2 Windows archive, or per-file LZMA2 compression describe the compression technology but not necessarily the surrounding archive workflow. Arqivexa combines LZMA2 storage with an Explorer-first editable .cfs format.
How ProjFS provides on-demand access → · Editable compressed archive concept →
04
What compression does not provide
Compression is not encryption or backup.
No archive encryption
Arqivexa 0.5 compresses archive contents but does not currently provide password protection or encryption.
No backup guarantee
A compressed archive is still one copy of data. Maintain independent backups of important files.
No universal format claim
LZMA2 is used inside Arqivexa's own .cfs structure. That does not make a .cfs archive interchangeable with 7z or another format that also uses LZMA2.
Current implementation
This page describes Arqivexa 0.5.0 Stable.
Format details can evolve in future versions. Use supported tooling for Arqivexa archives and do not infer compatibility solely from the underlying compression algorithm.