472 lines
12 KiB
Groff
472 lines
12 KiB
Groff
.\" Copyright (c) 1980, 1989, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)fstab.5 8.1 (Berkeley) 6/5/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 14, 2014
|
|
.Dt FSTAB 5
|
|
.Os
|
|
.Sh NAME
|
|
.Nm fstab
|
|
.Nd static information about the file systems
|
|
.Sh SYNOPSIS
|
|
.In fstab.h
|
|
.Sh DESCRIPTION
|
|
The file
|
|
.Nm
|
|
contains descriptive information about the various file
|
|
systems.
|
|
.Nm
|
|
is only read by programs, and not written;
|
|
it is the duty of the system administrator to properly create
|
|
and maintain this file.
|
|
Each file system is described on a separate line;
|
|
fields on each line are separated by tabs or spaces.
|
|
The order of records in
|
|
.Nm
|
|
is important because
|
|
.Xr fsck 8 ,
|
|
.Xr mount 8 ,
|
|
and
|
|
.Xr umount 8
|
|
sequentially iterate through
|
|
.Nm
|
|
doing their thing.
|
|
.Pp
|
|
The first field,
|
|
.Pq Fa fs_spec ,
|
|
describes the special device or
|
|
remote file system to be mounted.
|
|
The contents are decoded by the
|
|
.Xr strunvis 3
|
|
function.
|
|
This allows using spaces or tabs in the device name which would be
|
|
interpreted as field separators otherwise.
|
|
.Pp
|
|
The second field,
|
|
.Pq Fa fs_file ,
|
|
describes the mount point for the file system.
|
|
For swap partitions, this field should be specified as
|
|
.Dq none .
|
|
The contents are decoded by the
|
|
.Xr strunvis 3
|
|
function, as above.
|
|
.Pp
|
|
The third field,
|
|
.Pq Fa fs_vfstype ,
|
|
describes the type of the file system.
|
|
The system can support various file system types.
|
|
Only the root, /usr, and /tmp file systems need be statically
|
|
compiled into the kernel;
|
|
everything else will be automatically loaded at mount
|
|
time.
|
|
(Exception: the FFS cannot currently be demand-loaded.)
|
|
Some people still prefer to statically
|
|
compile other file systems as well.
|
|
.Pp
|
|
The fourth field,
|
|
.Pq Fa fs_mntops ,
|
|
describes the mount options associated with the file system.
|
|
It is formatted as a comma separated list of options.
|
|
It contains at least the type of mount (see
|
|
.Fa fs_type
|
|
below) plus any additional options appropriate to the file system type.
|
|
See the options flag
|
|
.Pq Fl o
|
|
in the
|
|
.Xr mount 8
|
|
page and the file system specific page, such as
|
|
.Xr mount_nfs 8 ,
|
|
for additional options that may be specified.
|
|
All options that can be given to the file system specific mount commands
|
|
can be used in
|
|
.Nm
|
|
as well.
|
|
They just need to be formatted a bit differently.
|
|
The arguments of the
|
|
.Fl o
|
|
option can be used without the preceding
|
|
.Fl o
|
|
flag.
|
|
Other options need both the file system specific flag and its argument,
|
|
separated by an equal sign.
|
|
For example, mounting an
|
|
.Xr msdosfs 5
|
|
filesystem, the options
|
|
.Bd -literal -offset indent
|
|
-o sync -o noatime -m 644 -M 755 -u foo -g bar
|
|
.Ed
|
|
.Pp
|
|
should be written as
|
|
.Bd -literal -offset indent
|
|
sync,noatime,-m=644,-M=755,-u=foo,-g=bar
|
|
.Ed
|
|
.Pp
|
|
in the option field of
|
|
.Nm .
|
|
.Pp
|
|
If the options
|
|
.Dq userquota
|
|
and/or
|
|
.Dq groupquota
|
|
are specified,
|
|
the file system is automatically processed by the
|
|
.Xr quotacheck 8
|
|
command, and user and/or group disk quotas are enabled with
|
|
.Xr quotaon 8 .
|
|
By default,
|
|
file system quotas are maintained in files named
|
|
.Pa quota.user
|
|
and
|
|
.Pa quota.group
|
|
which are located at the root of the associated file system.
|
|
These defaults may be overridden by putting an equal sign
|
|
and an alternative absolute pathname following the quota option.
|
|
Thus, if the user quota file for
|
|
.Pa /tmp
|
|
is stored in
|
|
.Pa /var/quotas/tmp.user ,
|
|
this location can be specified as:
|
|
.Bd -literal -offset indent
|
|
userquota=/var/quotas/tmp.user
|
|
.Ed
|
|
.Pp
|
|
If the option
|
|
.Dq failok
|
|
is specified,
|
|
the system will ignore any error which happens during the mount of that filesystem,
|
|
which would otherwise cause the system to drop into single user mode.
|
|
This option is implemented by the
|
|
.Xr mount 8
|
|
command and will not be passed to the kernel.
|
|
.Pp
|
|
If the option
|
|
.Dq noauto
|
|
is specified, the file system will not be automatically
|
|
mounted at system startup.
|
|
Note that, for network file systems
|
|
of third party types
|
|
(i.e., types supported by additional software
|
|
not included in the base system)
|
|
to be automatically mounted at system startup,
|
|
the
|
|
.Va extra_netfs_types
|
|
.Xr rc.conf 5
|
|
variable must be used to extend the
|
|
.Xr rc 8
|
|
startup script's list of network file system types.
|
|
.Pp
|
|
If the option
|
|
.Dq late
|
|
is specified, the file system will be automatically mounted
|
|
at a stage of system startup after remote mount points are mounted.
|
|
For more detail about this option,
|
|
see the
|
|
.Xr mount 8
|
|
manual page.
|
|
.Pp
|
|
If the option
|
|
.Dq update
|
|
is specified, it indicates that the status of an already mounted file
|
|
system should be changed accordingly.
|
|
This allows, for example, file systems mounted read-only to be upgraded
|
|
read-write and vice-versa.
|
|
By default, an entry corresponding to a file systems that is already
|
|
mounted is going to be skipped over when processing
|
|
.Nm ,
|
|
unless it's a root file system, in which case logic similar to
|
|
.Dq update
|
|
is applied automatically.
|
|
.Pp
|
|
The
|
|
.Dq update
|
|
option is typically used in conjunction with two
|
|
.Nm
|
|
files.
|
|
The first
|
|
.Nm
|
|
file is used to set up the initial set of file systems.
|
|
The second
|
|
.Nm
|
|
file is then run to update the initial set of file systems and
|
|
to add additional file systems.
|
|
.Pp
|
|
The type of the mount is extracted from the
|
|
.Fa fs_mntops
|
|
field and stored separately in the
|
|
.Fa fs_type
|
|
field (it is not deleted from the
|
|
.Fa fs_mntops
|
|
field).
|
|
If
|
|
.Fa fs_type
|
|
is
|
|
.Dq rw
|
|
or
|
|
.Dq ro
|
|
then the file system whose name is given in the
|
|
.Fa fs_file
|
|
field is normally mounted read-write or read-only on the
|
|
specified special file.
|
|
.Pp
|
|
If
|
|
.Fa fs_type
|
|
is
|
|
.Dq sw
|
|
then the special file is made available as a piece of swap
|
|
space by the
|
|
.Xr swapon 8
|
|
command at the end of the system reboot procedure.
|
|
For swap devices, the keyword
|
|
.Dq trimonce
|
|
triggers the delivery of a
|
|
.Dv BIO_DELETE
|
|
command to the device.
|
|
This command marks the device's blocks as unused, except those that
|
|
might store a disk label.
|
|
This marking can erase a crash dump.
|
|
To delay
|
|
.Nm swapon
|
|
for a device until after
|
|
.Nm savecore
|
|
has copied the crash dump to another location, use the
|
|
.Dq late
|
|
option.
|
|
For vnode-backed swap spaces,
|
|
.Dq file
|
|
is supported in the
|
|
.Fa fs_mntops
|
|
field.
|
|
When
|
|
.Fa fs_spec
|
|
is an
|
|
.Xr md 4
|
|
device file
|
|
.Pq Do md Dc or Do md[0-9]* Dc
|
|
and
|
|
.Dq file
|
|
is specified in
|
|
.Fa fs_mntopts ,
|
|
an
|
|
.Xr md 4
|
|
device is created with the specified file used as backing store,
|
|
and then the new device is used as swap space.
|
|
Swap entries on
|
|
.Pa .eli
|
|
devices will cause automatic creation of encrypted devices.
|
|
The
|
|
.Dq ealgo ,
|
|
.Dq aalgo ,
|
|
.Dq keylen ,
|
|
.Dq notrim ,
|
|
and
|
|
.Dq sectorsize
|
|
options may be passed to control those
|
|
.Xr geli 8
|
|
parameters.
|
|
The fields other than
|
|
.Fa fs_spec
|
|
and
|
|
.Fa fs_type
|
|
are unused.
|
|
If
|
|
.Fa fs_type
|
|
is specified as
|
|
.Dq xx
|
|
the entry is ignored.
|
|
This is useful to show disk partitions which are currently unused.
|
|
.Pp
|
|
The fifth field,
|
|
.Pq Fa fs_freq ,
|
|
is used for these file systems by the
|
|
.Xr dump 8
|
|
command to determine which file systems need to be dumped.
|
|
If the fifth field is not present, a value of zero is returned and
|
|
.Nm dump
|
|
will assume that the file system does not need to be dumped.
|
|
If the fifth field is greater than 0, then it specifies the number of days
|
|
between dumps for this file system.
|
|
.Pp
|
|
The sixth field,
|
|
.Pq Fa fs_passno ,
|
|
is used by the
|
|
.Xr fsck 8
|
|
and
|
|
.Xr quotacheck 8
|
|
programs to determine the order in which file system and quota
|
|
checks are done at reboot time.
|
|
The
|
|
.Fa fs_passno
|
|
field can be any value between 0 and
|
|
.Ql INT_MAX Ns -1 .
|
|
.Pp
|
|
The root file system should be specified with a
|
|
.Fa fs_passno
|
|
of 1, and other file systems should have a
|
|
.Fa fs_passno
|
|
of 2 or greater.
|
|
A file system with a
|
|
.Fa fs_passno
|
|
value of 1 is always checked sequentially and be completed before
|
|
another file system is processed, and it will be processed before
|
|
all file systems with a larger
|
|
.Fa fs_passno .
|
|
.Pp
|
|
For any given value of
|
|
.Fa fs_passno ,
|
|
file systems within a drive will be checked sequentially,
|
|
but file systems on different drives will be checked at the
|
|
same time to utilize parallelism available in the hardware.
|
|
Once all file system checks are complete for the current
|
|
.Fa fs_passno ,
|
|
the same process will start over for the next
|
|
.Fa fs_passno .
|
|
.Pp
|
|
If the sixth field is not present or is zero,
|
|
a value of zero is returned and
|
|
.Xr fsck 8
|
|
and
|
|
.Xr quotacheck 8
|
|
will assume that the file system does not need to be checked.
|
|
.Pp
|
|
The
|
|
.Fa fs_passno
|
|
field can be used to implement finer control when
|
|
the system utilities may determine that the file system resides
|
|
on a different physical device, when it actually does not, as with a
|
|
.Xr ccd 4
|
|
device.
|
|
All file systems with a lower
|
|
.Fa fs_passno
|
|
value will be completed before starting on file systems with a
|
|
higher
|
|
.Fa fs_passno
|
|
value.
|
|
E.g. all file systems with a
|
|
.Fa fs_passno
|
|
of 2 will be completed before any file systems with a
|
|
.Fa fs_passno
|
|
of 3 or greater are started.
|
|
Gaps are allowed between the different
|
|
.Fa fs_passno
|
|
values.
|
|
E.g. file systems listed in
|
|
.Pa /etc/fstab
|
|
may have
|
|
.Fa fs_passno
|
|
values such as 0, 1, 2, 15, 100, 200, 300, and may appear in any order
|
|
within
|
|
.Pa /etc/fstab .
|
|
.Bd -literal
|
|
#define FSTAB_RW "rw" /* read/write device */
|
|
#define FSTAB_RQ "rq" /* read/write with quotas */
|
|
#define FSTAB_RO "ro" /* read-only device */
|
|
#define FSTAB_SW "sw" /* swap device */
|
|
#define FSTAB_XX "xx" /* ignore totally */
|
|
|
|
struct fstab {
|
|
char *fs_spec; /* block special device name */
|
|
char *fs_file; /* file system path prefix */
|
|
char *fs_vfstype; /* File system type, ufs, nfs */
|
|
char *fs_mntops; /* Mount options ala -o */
|
|
char *fs_type; /* FSTAB_* from fs_mntops */
|
|
int fs_freq; /* dump frequency, in days */
|
|
int fs_passno; /* pass number on parallel fsck */
|
|
};
|
|
.Ed
|
|
.Pp
|
|
The proper way to read records from
|
|
.Pa fstab
|
|
is to use the routines
|
|
.Xr getfsent 3 ,
|
|
.Xr getfsspec 3 ,
|
|
.Xr getfstype 3 ,
|
|
and
|
|
.Xr getfsfile 3 .
|
|
.Sh FILES
|
|
.Bl -tag -width /etc/fstab -compact
|
|
.It Pa /etc/fstab
|
|
The file
|
|
.Nm
|
|
resides in
|
|
.Pa /etc .
|
|
.El
|
|
.Sh EXAMPLES
|
|
.Bd -literal
|
|
# Device Mountpoint FStype Options Dump Pass#
|
|
#
|
|
# UFS file system.
|
|
/dev/da0p2 / ufs rw 1 1
|
|
#
|
|
# Swap space on a block device.
|
|
/dev/da0p1 none swap sw 0 0
|
|
#
|
|
# Swap space using a block device with GBDE/GELI encryption.
|
|
# aalgo, ealgo, keylen, sectorsize options are available
|
|
# for .eli devices.
|
|
/dev/da1p1.bde none swap sw 0 0
|
|
/dev/da1p2.eli none swap sw 0 0
|
|
#
|
|
# tmpfs.
|
|
tmpfs /tmp tmpfs rw,size=1g,mode=1777 0 0
|
|
#
|
|
# UFS file system on a swap-backed md(4). /dev/md10 is
|
|
# automatically created. If it is "md", a unit number
|
|
# will be automatically selected.
|
|
md10 /scratch mfs rw,-s1g 0 0
|
|
#
|
|
# Swap space on a vnode-backed md(4).
|
|
md11 none swap sw,file=/swapfile 0 0
|
|
#
|
|
# CDROM. "noauto" option is typically used because the
|
|
# media is removable.
|
|
/dev/cd0 /cdrom cd9660 ro,noauto 0 0
|
|
#
|
|
# NFS-exported file system. "serv" is an NFS server name
|
|
# or IP address.
|
|
serv:/export /nfs nfs rw,noinet6 0 0
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr getfsent 3 ,
|
|
.Xr getvfsbyname 3 ,
|
|
.Xr strunvis 3 ,
|
|
.Xr ccd 4 ,
|
|
.Xr dump 8 ,
|
|
.Xr fsck 8 ,
|
|
.Xr geli 8 ,
|
|
.Xr mount 8 ,
|
|
.Xr quotacheck 8 ,
|
|
.Xr quotaon 8 ,
|
|
.Xr swapon 8 ,
|
|
.Xr umount 8
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
file format appeared in
|
|
.Bx 4.0 .
|