fstab(4)fstab(4)NAMEfstab - static information about the file systems
SYNOPSISDESCRIPTION
is an ASCII file that resides in directory
contains a list of mountable file-system entries. Each file-system
entry appears on a separate line, and consists of fields separated by
one or more blanks or tabs.
The order of entries in is important only for entries without a pass
number field. Entries without a pass number are sequentially checked
by (see fsck(1M)) after the entries with a pass number have been
checked.
Each file-system entry must contain a device special file and may addi‐
tionally contain all of the following fields, in the following order:
directory
type
options
backup frequency
pass number (on parallel
comment
If any field after the name of the device special file is present, all
fields must be present in the order indicated, to ensure correct place-
holding.
Entries from this file are accessed using (see getmntent(3X)).
The fields are separated by white space, and a as the first non-white‐
space character in an entry or field indicates a comment.
device special file A block device special file name. This field is
used by and other commands to identify the location
of the storage device on which the file system
resides. If type is this entry is ignored since a
block device is not required for a memory file sys‐
tem.
directory Name of the root of the mounted file system that
corresponds to the device special file. If type is
there is no corresponding device special file;
directory is the root of the memory based file sys‐
tem. If type is directory can be the name of any
directory within a file system. Only one directory
should be specified per file system. directory
must already exist and must be given as an absolute
path name.
type Can be or a file system type (for example, or
If type is the device special file is made avail‐
able as an area of swap space by the command (see
swapon(1M)). The options field is valid. The
fields directory, pass number, and backup frequency
are ignored for entries.
If type is the file system in which directory
resides is made available as swap space by The
options field is valid. The fields device special
file, pass number, and backup frequency are ignored
for entries.
If type is the device special file field is
ignored; the corresponding entry displayed in is
Additionally, if type is will skip the entry even
for matches of directory, if a different type is
specified to
If type is the device special file is made avail‐
able as an area into which a system crash dump may
occur, by the command (see crashconf(1M)). The
fields options, directory, pass number, and backup
frequency are ignored for entries.
Entries marked by the type are ignored by all com‐
mands and can be used to mark unused sections. If
type is specified as either or the entry is ignored
by the and commands (see mount(1M) and fsck(1M)).
fsck also ignores entries with type specified as or
options A comma-separated list of option keywords, as found
in or (see mount(1M) and swapon(1M)). The keywords
used depend on the parameter specified in type.
backup frequency Reserved for possible use by future backup utili‐
ties.
pass number Used by the command to determine the order in which
file system checks are done. The root file system
should be specified with a pass number of 1, to be
checked first, and other file systems should have
larger numbers. (A file system with a pass number
of zero is ignored by the command.)
File systems within a drive should be assigned dif‐
ferent pass numbers, but file systems on different
drives can be checked on the same pass, to utilize
possible parallelism available in the hardware. If
pass number is not present, checks each such file
system sequentially after all eligible file systems
with pass numbers have been checked.
comment An optional field that begins with a character and
ends with a new-line character. Space from the
pass number to the comment field (if present) or to
the new-line is reserved for future use.
There is no limit to the number of device special file fields in
NETWORKING FEATURES
NFS
If the field type is a remote NFS file system is implied. For NFS file
systems, the device special file should be the serving machine name
followed by ":" followed by the path on the serving machine of the
directory being served. The pass number and backup frequency fields
are ignored for NFS entries.
EXAMPLES
Examples of typical entries:
Add an HFS file system at using default mount options; (backup
frequency 0) fsck pass 2:
Add a device to a system managed using LVM, with default options
(Note, the directory field cannot be empty, even though it is
ignored):
Add a swap device on a system implementing whole-disk layout to
use the space after the end of the file system (options
Add file system swap space on the file system containing direc‐
tory type is set options to and (see swapon(1M)) for explanation
of options). device field is ignored but must not be empty:
(Note that both a file system entry and a swap entry are
required for devices providing both services.)
Use a device for dump space if the system crashes. directory
field is ignored but must not be empty:
(Note that both a swap entry and a dump entry are required for
devices providing both services.)
Add a MemFS file system at of The device special file field is
ignored but must not be empty:
WARNINGS
HP-UX system administration tools that provide file system mount man‐
agement interfaces may read and/or write System administrators should
be careful not to simultaneously modify this file with one of these
tools.
DEPENDENCIES
NFS
Here is an example for mounting an NFS file system on systems that sup‐
port NFS file systems:
AUTHORfstab was developed by HP, AT&T, Sun Microsystems, Inc., and the Uni‐
versity of California, Berkeley.
FILESSEE ALSOcrashconf(1M), fsck(1M), mount(1M), swapon(1M), getfsent(3X), getmn‐
tent(3X), mnttab(4).
fstab(4)
