vfs File

Purpose

Describes the virtual file systems (VFS) installed on the system.

Description

The /etc/vfs file describes the virtual file systems installed on the
system. The name, type number, and file-system helper program are among the
types of information listed in the file. Commands, such as the mount
command, the fsck
command (file system check), and the mkfs command (make file system),
use this information.

The vfs file is an ASCII file, with one record per line. The following are
examples of the three types of lines in the vfs file:

    Comments

    # This is a comment.
    # Comments begin with a # (pound sign).
    # Blank lines are ignored.
    # The following example only locally defines the default vfs file.

    General control

    %defaultvfs jfs nfs

    The fields for the %defaultvfs control line are:
     %defaultvfs
                Identifies the control line.
     jfs
                Indicates the default local virtual file system.
     nfs
                Indicates the remote virtual file system (optional).

    Entries

    #Name   Type   Mount Helper      Fs. helper
    jfs      3     none               /sbin/helpers/v3fshelper
    nfs      2     /etc/nfsmnthelp    none
    cdrfs    5     none               none

The comments are in text for explanatory purposes. The general control
lines, which are designated by a % (percent) character, configure the
actions of the following commands:

    mount
    umount
    mkfs
    fsck
    fsdb
    df
    ff

For example, a line like %defaultvfs indicates the default local virtual
file system is used if no VFS is specified by the mount command or in the
/etc/filesystems file. The entry is the name of the VFS as indicated in the
file. If a second entry is listed on the same line, it is taken to be the
default remote
VFS. The %defaultvfs control line may leave off the remote VFS
specification.

The VFS entries take the following form:

 name
           Canonical name of this type of virtual file system.
 type
           Decimal representation of the virtual file system type number
for the VFS.
 mnt_helper
           Path name of the mount helper program of this VFS. If a mount
helper is not required, the entry should be displayed as none . If this
path
           name does not begin with a slash, it is relative to the
/sbin/helpers directory.
 fs_helper
           Path name of the file system helper program of this VFS. If a
file system helper is not required, the entry should be none . If this path
name
           does not begin with a slash, it is relative to the /sbin/helpers
directory.


Implementation Specifics

This file is part of the Base Operating System (BOS) Runtime.

Files

 /etc/filesystems
            Lists the known file systems and defines their characteristics.


Related Information

The chvfs command, crvfs command, df command, ff command, fsck command,
fsdb
command, lsvfs command, mkfs command, mount command,
rmvfs command, umount command.

The File Systems Overview for System Management in AIX Version 4.3 System
Management Guide: Operating System and Devices explains file system
types, management, structure, and maintenance.