volfs(7FS)                                                         File Systems                                                         volfs(7FS)

NAME

       volfs - Volume Management file system

DESCRIPTION

       volfs  is the Volume Management file system rooted at root_dir. The default location for root-dir is /vol, but this can be overridden using
       the -d option of vold (see vold(1M)). This file system is maintained by the Volume Management daemon, vold, and will be  considered  to  be
       /vol for this description.

       Media  can  be  accessed  in a logical manner (no association with a particular piece of hardware), or a physical manner (associated with a
       particular piece of hardware).

       Logical names for media are referred to through /vol/dsk and /vol/rdsk. /vol/dsk provides block access to random access devices.  /vol/rdsk
       provides character access to random access devices.

       The /vol/rdsk and /vol/dsk directories are mirrors of one another. Any change to one is reflected in the other immediately. The dev_t for a
       volume will be the same for both the block and character device.

       The default permissions for /vol are mode=0555, owner=root, group=sys. The default permissions for /vol/dsk and /vol/rdsk  are  mode=01777,
       owner=root, group=sys.

       Physical  references to media are obtained through /vol/dev. This hierarchy reflects the structure of the /dev name space. The default per-
       missions for all directories in the /vol/dev hierarchy are mode=0555, owner=root, group=sys.

       mkdir(2), rmdir(2), unlink(2) (rm), symlink(2) (ln -s), link(2) (ln), and rename(2) (mv) are supported, subject to normal file  and  direc-
       tory permissions.

       The following system calls are not supported in the /vol filesystem: creat(2), only when creating a file, and mknod(2).

       If the media does not contain file systems that can be automatically mounted by rmmount(1M), users can gain access to the media through the
       following /vol locations:

       +-----------------------------------+------------------------------------+
       |             Location              |           State of Media           |
       +-----------------------------------+------------------------------------+
       |/vol/dev/diskette0/unnamed_floppy  | formatted   unnamed   floppy-block |
       |                                   | device access                      |
       +-----------------------------------+------------------------------------+
       |/vol/dev/rdiskette0/unnamed_floppy | formatted    unnamed    floppy-raw |
       |                                   | device access                      |
       +-----------------------------------+------------------------------------+
       |/vol/dev/diskette0/unlabeled       | unlabeled   floppy-block    device |
       |                                   | access                             |
       +-----------------------------------+------------------------------------+
       |/vol/dev/rdiskette0/unlabeled      | unlabeled floppy-raw device access |
       +-----------------------------------+------------------------------------+
       |/vol/dev/dsk/c0t6/unnamed_cdrom    | CD-ROM-block device access         |
       +-----------------------------------+------------------------------------+
       |/vol/dev/rdsk/c0t6/unnamed_cdrom   | CD-ROM-raw device access           |
       +-----------------------------------+------------------------------------+

       For more information on the location of CD-ROM and floppy media, see System Administration Guide: Basic Administration or rmmount(1M).

   Partitions
       Some  media  support the concept of a partition. If the label identifies partitions on the media, the name of the media becomes a directory
       with partitions under it. Only valid partitions are represented.  Partitions cannot be moved out of a directory.

       For example, if disk volume 'foo' has three valid partitions, 0, 2, and 5, then:

       /vol/dsk/foo/s0
       /vol/dsk/foo/s2
       /vol/dsk/foo/s5

        for block access and

       /vol/rdsk/foo/s0
       /vol/rdsk/foo/s2
       /vol/rdsk/foo/s5

        for character access.

       If a volume is relabeled to reflect different partitions, the name space changes to reflect the new partition layout.

       A format program can check to see if there are others with the volume open and not allow the format to occur if it is.  Volume  Management,
       however,  does  not  explicitly prevent the rewriting of a label while others have the volume open. If a partition of a volume is open, and
       the volume is relabeled to remove that partition, it will appear exactly as if the volume were missing. A notify event  will  be  generated
       and the user may cancel the operation with volcancel(1), if desired.

SEE ALSO

       volcancel(1), volcheck(1), volmissing(1) rmmount(1M), vold(1M), rmmount.conf(4), vold.conf(4)

        System Administration Guide: Basic Administration

SunOS 5.10                                                          8 Feb 1995                                                          volfs(7FS)