Administering filesystems

cdfs advanced mount options

When you add or modify a CDFS filesystem you can set advanced options for this filesystem type. The advanced options are divided into two groups, Extension and Supplemental. The significance of the division will become apparent below when descibing the different ways to apply the options. The Filesystem Manager supports the following options:

Extension Related Options

Extensions to ISO-9660/High Sierra

Enable/Disable the processing of all extensions to the ISO-9660/High Sierra specification (SUSP and non-SUSP alike). By default cdfs mount enables the processing of all extensions to the ISO-9660/High Sierra specification.

NOTE: After CDFS mounts an ISO-9660 CD-ROM or a CD-ROM image, only one of the extensions (i.e. either RRIP, Joliet, or Pure ISO-9660) will be Active. How an extension becomes the Active Extension is determined by:

the set of extensions enabled for processing at mount time (i.e. set consisting of RRIP, Joliet, and Pure ISO-9660 (set by disabling the processing of all extensions to ISO-9660)).
the set of extensions that exist on the CD-ROM media.
applying a set of rules as described in mount_cdfs(ADM) to the set of enabled and existing extensions.

System Use Sharing Protocol

Enable/disable the processing of all System Use Sharing Protocol (SUSP) compliant extensions to the ISO-9660/High Sierra specification. The SUSP defines a mechanism for which the System Use Area (SUA) of a Directory Record (DREC) may be shared by multiple independent organizations, such as the Rockridge Interchange Protocol (RRIP). DRECs are elements of a CD-ROM Directory Hierarchy which is managed by a Volume Descriptor (either the Primary Volume Descriptor (PVD) or a Supplementary Volume Descriptor (SVD) if any exist). By default cdfs mount enables the processing of SUSP.

NOTE: The CDFS filesystem implementation only supports SUSP and compliant SUSP extensions (i.e. RRIP) on DREC SUAs that are managed by the (PVD) It does not support SUSP on DREC SUAs that is managed by any SVD such as a SVD that is supporting Joliet extensions for example.

Rockridge Interchange Protocol

Enable/disable the processing of all Rockridge Interchange Protocol (RRIP) extensions to the ISO-9660/High Sierra specification. The RRIP is a SUSP-compliant set of extensions that provide POSIX file semantics. By default, cdfs mount enables the processing of RRIP.

Joliet

Enable/Disable the processing of the Joliet extensions to the ISO-9660/High Sierra specification. Joliet utilizes the Supplementary Volume Descriptor (SVD) feature of the ISO-9660/High Sierra specification to manage a Directory Hierarchy and by doing so eliminates several ISO-9660/High Sierra restrictions such as File/Directory Identifiers lengths, character sets (Identifiers are recored within the Unicode (i.e. ISO10646) character set), and Directory Hierarch depth. By default, cdfs mount enables the processing of Joliet.

Supplemental Related Options

Filename Conversion

There are three possible options for altering the diplay of filenames recorded on a ISO-9660 CD-ROM media or image:

Do not alter the filename. This option is mutually exclusive with the next two options.
Display filenames in lowercase and suppresses any trailing period (.) characters.
Suppress the display of version numbers and separators (;).

The default is to do options 2 & 3. If filenames have been recorded as POSIX filenames (i.e. the RRIP extension) and RRIP is the Active Extension, option 2 and 3 have no effect. If filenames have been recorded as Joliet filenames and Joliet is the Active Extension, option 2 has no effect.

Grant Directory Search Permission to use who has

Determines the search permissions for a directory (as recorded on the CD-ROM or defined by the Default File Permissions option): execute permissions only, or read and execute.

Default File Permissions

Sets the permissions for files recorded without permissions (as defined in an extended attribute record, or XAR, the optional data structure used within an ISO9660 format CD-ROM for recording file attributes). Specify the mode in octal. See chmod(C). The default permissions are set to 0444.

Default Directory Permissions

Sets the permissions for directories recorded without permissions. Specify the mode in octal. See chmod(C). The default permissions are set to 0555.

Default User (Name or ID)

Defines the default user for files and directories that are recorded without ownership. If you set this option, you must use a valid user name or a valid user ID between 0 and 60002. If you do not set this option, the files are recorded with the user ID of the mount point for the filesystem.

Default Group (Name or ID)

Defines the default group for files and directories recorded without this information. If you set this option, you must use a valid group name or a valid group ID between 0 and 60002. If you do not set this option, the files are recorded with the group ID of the mount point for the filesystem.

User ID Mapping

Maps the user ID recorded on the CD-ROM to a user ID on the system. If you set this option, you must use a valid user name or a valid user ID between 0 and 60002.

Group ID Mapping

Maps the group ID recorded on the CD-ROM to a group ID on the system. If you set this option, you must use a valid group name or a valid group ID between 0 and 60002.

Device ID Mapping

Maps the device number recorded on the CD-ROM to a device number on the system. If you specify this option, the device pathname must be a full pathname from the root of the CD-ROM. The major device number on the system must be a valid device number in the range of 0 to 8191. The minor device number on the system must be a valid device number in the range of 0 to 262143.

NOTE: The Filesystem Manager only supports device ID mapping options for Rockridge filesystems.

Mapping CD-ROM files to system entities

You can map devices names, users and groups found on a mounted CD-ROM filesystem to entities found on the system. For example, by default the system assigns unknown user or group IDs on a mounted CD-ROM to user nobody.

To set the default user or group ID, select the CD-ROM filesystem in the Filesystem Manager and select Mount Modify Mount Configuration Set more options. Enter or select a Default User or Default Group.

To map specific entities (including device names), select the appropriate Mapping button. Enter a filename for the mapping file, or use the Browse button to select an existing file:

To add an entry, use the Add button and enter an ID number or device path and select (or enter) a system ID or device number.
To modify an entry, select it from the list and use the Modify button.
To delete an entry, select it from the list and use the Remove button.

Option Persistence

cdfs advanced mount options can be applied persistently or non-persistently. A cdfs advanced mount option designated persistent has its value stored in /etc/default/filesys when the option is applied and the option will be reapplied upon subsequent mounts. A cdfs advanced mount option designated non-persistent does not have its value stored in /etc/default/filesys. The option is applied only once for the current mount/remount and is not reapplied on subsequent mounts. Option persistence characteristics are user settable and are highlighted in the color yellow thereby making them easy to distinguish from non-persistent options.

Applying CDFS Advanced Mount Options

All Supplemental Related advanced mount options can be applied to a mounted cdfs filesystem (i.e. there is no need to re-mount, (i.e umount then mount)). The Supplemental Related options can also be applied when re-mounting the filesystem. All Extension Related advanced mount options can only be applied by re-mounting the filesystem. Attempting to apply changed Extension Related options to a currently mounted cdfs filesystem will have no effect. To apply Supplemental Related options to a currently mounted cdfs filesystem:

Select the CD-ROM filesystem in the Filesystem Manager.
Select Mount Modify Mount Configuration Set more options...
After selecting desired advanced mount options, select the OK button in the Advanced Options for Mounting CD-ROM window.
Select the OK button in the Modify Mount Configuration window.
Select the No button in the Do you want to re-mount with new settings now? question window.
Select the Yes button in the Do you want to apply new settings to filesystem without remounting? question window.