cdfs(4)cdfs(4)NAMEcdfs - The Compact Disk-Read Only Memory File System (CDFS)
DESCRIPTION
The ISO 9660 standard describes volume and file structures for informa‐
tion exchange on a Compact Disk-Read Only Memory (CD-ROM) volume. CDFS
supports mounting, as another local file system type, CD-ROMs that com‐
ply 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 Interchange Level 2
with the exception of multiple volume semantics, which are supported.
Refer to the international standard ISO 9660-1988 for additional infor‐
mation pertaining to the actual standard.
The CDFS behaves the same as any read-only file system, and addition‐
ally supports the following semantics: The CDFS can be exported by NFS
Users can mount other file system types (UFS, NFS, AdvFS) onto directo‐
ries recorded on a CD-ROM volume CD-ROM volumes can be recorded in ISO
9660-1988, Interchange level 2, or (for backward compatibility) High
Sierra Group (HSG) format The data on a CD-ROM volume that is recorded
as part of a multiple volume set or consists of a single volume is made
available when the volume is mounted File systems on a CD-ROM volume
can be accessed locally and remotely The CDFS can be organized on a CD-
ROM volume in multiple sessions. The contents of all sessions is
available as one file system; individual sessions are not separately
available.
The CDFS also supports CD-ROMs recorded using the Rock Ridge Inter‐
change Protocol, Revision 1.09, August 1991. Rock Ridge specifies the
use of the extension fields that are defined by ISO-9660:1988, and it
uses those extensions to provide the following information: File owner,
file group, file permissions Additional file types (symbolic links,
device special files, named pipes) setuid, setgid, and sticky bits Hard
link counts POSIX file names (mixed case names, unstructured names, and
longer names than ISO-9660:1988 allows) Deep directory hierarchies
(greater than 8 levels) File time stamps
Refer to the Rock Ridge specification for additional information about
the extensions.
The CDFS also supports the XCDR extensions (X/Open Preliminary Specifi‐
cation (1991) CD-ROM Support Component). These XCDR extensions add the
following support: Users can examine selected ISO 9660 attributes
through defined utilities and shared libraries A system administrator
can substitute different file protections, owners, and file names for
files on a CD-ROM volume.
RELATED INFORMATIONmount(8), cddevsuppl(8), cdsuf(1), cd_getdevmap(3), cd_setdevmap(3),
and cd_suf(3) delim off
cdfs(4)