cdfs - The Compact Disk-Read Only Memory File System
(CDFS)
The ISO 9660 standard describes volume and file structures
for information exchange on a Compact Disk-Read Only Memory
(CD-ROM) volume. CDFS supports mounting, as another
local file system type, CD-ROMs that 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 Interchange Level 2 with the exception of multiple
volume semantics, which are supported. Refer to the
international standard ISO 9660-1988 for additional information
pertaining to the actual standard.
The CDFS behaves the same as any read-only file system,
and additionally supports the following semantics: The
CDFS can be exported by NFS Users can mount other file
system types (UFS, NFS, AdvFS) onto directories 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 CDROM
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 Interchange 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
Specification (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.
mount(8), cddevsuppl(8), cdsuf(1), cd_getdevmap(3),
cd_setdevmap(3), and cd_suf(3) delim off
cdfs(4)
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