Zisofs

zisofs is an extension of ISO 9660 format, which adds support for per-file compression.

It is designed as an extension of Rock Ridge. It specifies a new entry, with signature " ".

For the apparent predecessor of zisofs, see Isofs transparent compression.

Identification
Use of zisofs requires that SUSP and Rock Ridge be enabled (see System Use Sharing Protocol). Determining whether a volume actually uses zisofs would require scanning every directory.

zisofs-compressed files use a special format, with signature bytes. Files in this format could be visible if zisofs is not supported, or as part of some workflows for creating a zisofs volume.

Software

 * libarchive / bsdtar
 * Supported by Linux filesystem drivers
 * zisofs-tools

Links

 * https://dev.lovelyhq.com/libburnia/web/wikis/zisofs