hsfs(7FS)							   File Systems 							 hsfs(7FS)

NAME

       hsfs - High Sierra & ISO 9660 CD-ROM file system

DESCRIPTION

       HSFS  is a file system type that allows users access to files on High Sierra or	ISO 9660 format CD-ROM disks from within the SunOS operat-
       ing system. Once mounted, a HSFS file system provides standard SunOS read-only file system operations and semantics.  That  is,	users  can
       read  files and list files in a directory on a High Sierra or ISO 9660 CD-ROM, and applications can use standard UNIX system calls on these
       files and directories.

       This file system also contains support for the Rock Ridge Extensions. If  the extensions  are contained on the  CD-ROM, then the file  sys-
       tem will provide all of the file system semantics and file types of  UFS, except for writability and hard links.

       If  your /etc/vfstab file contains a line similar to

       /dev/dsk/c0t6d0s0 -/hsfs hsfs -no ro

       and /hsfs exists, you can mount an HSFS file system with either of the following commands:

       mount -F hsfs -o ro device-special directory-name

       or

       mount /hsfs

       Normally,  if  Rock  Ridge extensions exist on the  CD-ROM, the file system will automatically use those extensions.  If you do not want to
       use the Rock Ridge extensions, use the ``nrr'' (No Rock Ridge) mount option. The mount command would then be:

       mount -F hsfs -o ro,nrr device-special directory-name

       Files on a High Sierra or ISO 9660 CD-ROM disk have names of the form filename.ext;version, where  filename and the optional   ext  consist
       of  a sequence of uppercase alphanumeric characters (including ``_''), while the version consists of a sequence of digits, representing the
       version number of  the file. HSFS converts all the uppercase characters in a file name to lowercase, and truncates the  ``;''  and  version
       information.  If more than one version of a file is present on the  CD-ROM, only the file with the highest version number is accessible.

       Conversion of uppercase to lowercase characters may be disabled by using the -o nomaplcase option to mount(1M). (See mount_hsfs(1M)).

       If  the	 CD-ROM  contains  Rock  Ridge extensions, the file names and directory names may contain any character supported under  UFS.  The
       names may also be upper and/or lower case and will be case sensitive.  File name lengths can be as long as those of  UFS.

       Files accessed through HSFS have mode 555 (owner, group and world readable and executable),  uid 0 and gid 3. If a directory on the  CD-ROM
       has read permission, HSFS grants execute permission to the directory, allowing it to be searched.

       With  Rock  Ridge extensions, files and directories can have any permissions that are supported on a  UFS file system; however, despite any
       write permissions, the file system is read-only, with EROFS returned to any write operations.

       High Sierra and ISO 9660 CD-ROMs support only regular files and directories, thus HSFS supports only these file types.  A Rock Ridge CD-ROM
       can support regular files, directories, and symbolic links, as well as device nodes, such as block, character, and FIFO.

EXAMPLES

       Example 1: Sample Display of File System Files

       If there is a file BIG.BAR on a High Sierra or ISO 9660 format CD-ROM it will show up as big.bar when listed on a HSFS file system.

       If there are three files

       BAR.BAZ;1

       BAR.BAZ;2

	and

       BAR.BAZ;3

       on a High Sierra or ISO 9660 format CD-ROM, only the file BAR.BAZ;3 will be accessible. It will be listed as bar.baz.

SEE ALSO

       mount(1M), mount_hsfs(1M), vfstab(4)

       N. V. Phillips and Sony Corporation, System Description Compact Disc Digital Audio, ("Red Book").

       N. V. Phillips and Sony Corporation, System Description of Compact Disc Read Only Memory, ("Yellow Book").

       IR "Volume and File Structure of CD-ROM for Information Interchange", ISO 9660:1988(E).

DIAGNOSTICS

       hsfs: Warning: the file system...
       does not conform to the ISO-9660 spec

	   The	specific  reason appears on the following line. You might be attempting to mount a CD-ROM containing a different file system, such
	   as UFS.

       hsfs: Warning: the file system...
       contains a file [with an] unsupported type

	   The hsfs file system does not support the format of some file or directory on the CD-ROM, for example a record structured file.

       hsfs: hsnode table full, %d nodes allocated

	   There are not enough HSFS internal data structure elements to handle all the files currently open.  This problem  may  be  overcome	by
	   adding a line of the form set hsfs:nhsnode=number to the /etc/system system configuration file and rebooting.  See system(4).

WARNINGS

       Do not physically eject a CD-ROM while the device is still mounted as a HSFS file system.

       Under MS-DOS (for which CD-ROMs are frequently targeted), files with no extension may be represented either as

       filename.

       or

       filename

       that is, with or without a trailing period. These names are not equivalent under UNIX systems. For example, the names

       BAR.

       and

       BAR

       are  not names for the same file under the UNIX system. This may cause confusion if you are consulting documentation for CD-ROMs originally
       intended for MS-DOS systems.

       Use of the -o notraildot option to mount(1M) makes it optional to specify the trailing dot. (See mount_hsfs(1M)).

NOTES

       No translation of any sort is done on the contents of High Sierra or ISO 9660 format CD-ROMs; only directory and file names are subject	to
       interpretation by HSFS.

SunOS 5.10							    25 Apr 1994 							 hsfs(7FS)