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diff --git a/sys-utils/fstab.5 b/sys-utils/fstab.5 new file mode 100644 index 0000000..a9e9f8c --- /dev/null +++ b/sys-utils/fstab.5 @@ -0,0 +1,248 @@ +.\" Copyright (c) 1980, 1989, 1991 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. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. 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 6.5 (Berkeley) 5/10/91 +.\" +.TH FSTAB 5 "February 2015" "util-linux" "File Formats" +.SH NAME +fstab \- static information about the filesystems +.SH SYNOPSIS +.I /etc/fstab +.SH DESCRIPTION +The file +.B fstab +contains descriptive information about the filesystems the system can mount. +.B fstab +is only read by programs, and not written; it is the duty of the system +administrator to properly create and maintain this file. The order of records in +.B fstab +is important because +.BR fsck (8), +.BR mount (8), +and +.BR umount (8) +sequentially iterate through +.B fstab +doing their thing. + +Each filesystem is described on a separate line. +Fields on each line are separated by tabs or spaces. +Lines starting with '#' are comments. Blank lines are ignored. +.PP +The following is a typical example of an +.B fstab +entry: +.sp +.RS 7 +LABEL=t-home2 /home ext4 defaults,auto_da_alloc 0 2 +.RE + +.B The first field +.RI ( fs_spec ). +.RS +This field describes the block special device or +remote filesystem to be mounted. +.LP +For ordinary mounts, it will hold (a link to) a block special +device node (as created by +.BR mknod (8)) +for the device to be mounted, like `/dev/cdrom' or `/dev/sdb7'. +For NFS mounts, this field is <host>:<dir>, e.g., `knuth.aeb.nl:/'. +For filesystems with no storage, any string can be used, and will show up in +.BR df (1) +output, for example. Typical usage is `proc' for procfs; `mem', `none', +or `tmpfs' for tmpfs. Other special filesystems, like udev and sysfs, +are typically not listed in +.BR fstab . +.LP +LABEL=<label> or UUID=<uuid> may be given instead of a device name. +This is the recommended method, as device names are often a coincidence +of hardware detection order, and can change when other disks are added or removed. +For example, `LABEL=Boot' or `UUID=3e6be9de\%-8139\%-11d1\%-9106\%-a43f08d823a6'. +(Use a filesystem-specific tool like +.BR e2label (8), +.BR xfs_admin (8), +or +.BR fatlabel (8) +to set LABELs on filesystems). + +It's also possible to use PARTUUID= and PARTLABEL=. These partitions identifiers +are supported for example for GUID Partition Table (GPT). + +See +.BR mount (8), +.BR blkid (8) +or +.BR lsblk (8) +for more details about device identifiers. + +.LP +Note that +.BR mount (8) +uses UUIDs as strings. The string representation of the UUID should be based on +lower case characters. +.RE + +.B The second field +.RI ( fs_file ). +.RS +This field describes the mount point (target) for the filesystem. For swap partitions, this +field should be specified as `none'. If the name of the mount point +contains spaces or tabs these can be escaped as `\\040' and '\\011' +respectively. +.RE + +.B The third field +.RI ( fs_vfstype ). +.RS +This field describes the type of the filesystem. Linux supports many +filesystem types: ext4, xfs, btrfs, f2fs, vfat, ntfs, hfsplus, +tmpfs, sysfs, proc, iso9660, udf, squashfs, nfs, cifs, and many more. +For more details, see +.BR mount (8). + +An entry +.I swap +denotes a file or partition to be used +for swapping, cf.\& +.BR swapon (8). +An entry +.I none +is useful for bind or move mounts. + +More than one type may be specified in a comma-separated list. + +.BR mount (8) +and +.BR umount (8) +support filesystem +.IR subtypes . +The subtype is defined by '.subtype' suffix. For +example 'fuse.sshfs'. It's recommended to use subtype notation rather than add +any prefix to the first fstab field (for example 'sshfs#example.com' is +deprecated). +.RE + +.B The fourth field +.RI ( fs_mntops ). +.RS +This field describes the mount options associated with the filesystem. + +It is formatted as a comma-separated list of options. +It contains at least the type of mount +.RB ( ro +or +.BR rw ), +plus any additional options appropriate to the filesystem +type (including performance-tuning options). +For details, see +.BR mount (8) +or +.BR swapon (8). + +Basic filesystem-independent options are: +.TP +.B defaults +use default options: rw, suid, dev, exec, auto, nouser, and async. +.TP +.B noauto +do not mount when "mount -a" is given (e.g., at boot time) +.TP +.B user +allow a user to mount +.TP +.B owner +allow device owner to mount +.TP +.B comment +or +.B x-<name> +for use by fstab-maintaining programs +.TP +.B nofail +do not report errors for this device if it does not exist. +.RE + +.B The fifth field +.RI ( fs_freq ). +.RS +This field is used by +.BR dump (8) +to determine which filesystems need to be dumped. +Defaults to zero (don't dump) if not present. +.RE + +.B The sixth field +.RI ( fs_passno ). +.RS +This field is used by +.BR fsck (8) +to determine the order in which filesystem checks are done at +boot time. The root filesystem should be specified with a +.I fs_passno +of 1. Other filesystems should have a +.I fs_passno +of 2. Filesystems within a drive will be checked sequentially, but +filesystems on different drives will be checked at the same time to utilize +parallelism available in the hardware. +Defaults to zero (don't fsck) if not present. + +.SH NOTES +The proper way to read records from +.B fstab +is to use the routines +.BR getmntent (3) +or +.BR libmount . + +The keyword +.B ignore +as a filesystem type (3rd field) is no longer supported by the pure +libmount based mount utility (since util-linux v2.22). + +.SH FILES +.IR /etc/fstab , +.I <fstab.h> +.SH "SEE ALSO" +.BR getmntent (3), +.BR fs (5), +.BR findmnt (8), +.BR mount (8), +.BR swapon (8) +.SH HISTORY +The ancestor of this +.B fstab +file format appeared in 4.0BSD. +.\" But without comment convention, and options and vfs_type. +.\" Instead there was a type rw/ro/rq/sw/xx, where xx is the present 'ignore'. +.SH AVAILABILITY +This man page is part of the util-linux package and is available from +https://www.kernel.org/pub/linux/utils/util-linux/. |