ISO-9660 filesystem support (with extensions)


driver ... cd cd_options ... &


Where driver is one of the devb-* drivers, and cd_options is one or more of the following, separated by commas:

Control the case used to display ISO-9660 filenames (to a readdir() request; all pathname matching is always performed case-insensitively on such names):
  • asis — don't convert the filename in any way; if the CD was mastered with strict ISO-9660 compliance, the name will be in uppercase, but more lenient utilities could produce mixed-case filenames.
  • lower — convert to lowercase (the default).
  • upper — convert to uppercase.

RRIP and Joliet store case-preserving names and ignore this option.

Set execute permission (on all non-RRIP regular files).
gid= group
Set the owning group to group for files on disks without Rock Ridge extensions. The default is 0 (root).
hidden= hidden_mode
Specify what to do with hidden files. The hidden_mode can be one of:
  • ignore — ignore the hidden files; they don't appear in the filesystem.
  • show — (the default) show hidden files in the filesystem as normal files.
  • dot — show hidden files in the filesystem with a dot (.) prefixed to their names.
info= path
The name of the information pseudo-directory (the default is -.info.).

If the option is empty, no metadata directory is created. If the option begins with a -, then blank metadata fields are hidden; if the option begins with a +, then all metadata fields are presented but may have a length of zero.

Disable audio extensions (the .info./audio control file).
Disable High Sierra format.
Disable Microsoft Joliet extensions.
Disable multisession support (mount the first data session instead of the last).
Disable Rock Ridge extensions.
uid= user
Set the owner to user for files on disks without Rock Ridge extensions. The default is 0 (root).
umask= mask
Apply this permission mask to files on disks without Rock Ridge extensions. The default is 0 (all access permissions).

In addition, you can specify any of the filesystem options described for io-blk.so .


The fs-cd.so shared object provides support for ISO-9660 filesystems. It's automatically loaded by the devb-* drivers when mounting an ISO-9660 filesystem.

  • This filesystem uses UTF-8 encoding for presentation of its filenames; attempts to specify a filename not using UTF-8 encoding will fail (with an error of EILSEQ).
  • We've deprecated fs-cd.so in favor of fs-udf.so , which now supports ISO-9660 filesystems in addition to UDF.