cdfs(4) — File Formats
Digital
NAME
cdfs − The CD-ROM (Compact Disc Read Only Memory) File System
DESCRIPTION
The ISO 9660 standard describes volume and file structures for information exchange on CD-ROM’s. CDFS supports mounting, as another local file system type, CD-ROM’s which comply to the standard. Once mounted, files and directories recorded on the CD-ROM become accessible in a read-only manner through system calls and commands. Support of the standard is limited to level 2 interchange with the exeception of multiple volume semantics, according to ISO 9660. Refer to the international standard ISO 9660-1988 for addtional information pertaining to the actual standard.
The CDFS file system behaves the same as any read-only file system, and additionally supports the following semantics. The CDFS can be exported by NFS, and supports users being able to mount other file system types (UFS, NFS, CDFS) onto directories recorded on the CDFS volume. Volumes recorded in ISO 9660-1988 (interchange level 2) or High Sierra Group (HSG) format are supported. The data of a mounted volume which is recorded as part of a multiple volume set or consists of a single volume set is made available. Both local and remote execution is supported for non-interleaved files. Data contained in files recorded in interleave mode and non-interleave mode is available through read(2). If demand page execution of interleaved files is required, the user can either copy the file to magnetic storage, or execute the file over NFS.
Since CDFS is a configurable kernel option, the following two lines must exist in the systems configuration file:
options CDFS
pseudo-devicecdfs
If the system configuration does not contain the above lines, modify the configuration file and rebuild the kernel.