I proofread the whole thing. I fixed everything that I thought could use improvement. various grammar fixes (commas, word order, etc.). Added an example line. Reworded a couple things to hopefully make it clear to someone that didn't already know about fstab. Expanded on a couple things. Tightened up the wording in some other places to get the point across faster and in less space. Updated the date. Signed-off-by: Peter Cordes <peter@xxxxxxxxx> --- sys-utils/fstab.5 | 85 +++++++++++++++++++++++++++++++------------------------ 1 file changed, 48 insertions(+), 37 deletions(-) diff --git a/sys-utils/fstab.5 b/sys-utils/fstab.5 index 9287519..4f5369c 100644 --- a/sys-utils/fstab.5 +++ b/sys-utils/fstab.5 @@ -31,7 +31,7 @@ .\" .\" @(#)fstab.5 6.5 (Berkeley) 5/10/91 .\" -.TH FSTAB 5 "August 2010" "util-linux" "File Formats" +.TH FSTAB 5 "February 2015" "util-linux" "File Formats" .SH NAME fstab \- static information about the filesystems .SH SYNOPSIS @@ -39,12 +39,12 @@ fstab \- static information about the filesystems .SH DESCRIPTION The file .B fstab -contains descriptive information about the various file systems. +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. 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. The +spaces. Lines starting with '#' are comments. Blank lines are ignored. The order of records in .B fstab is important because @@ -56,27 +56,38 @@ sequentially iterate through .B fstab doing their thing. +This is a typical example of an +.B fstab +entry: +.sp 1 +LABEL=t-home2 /home ext4 defaults,auto_da_alloc 0 2 + .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 +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 one will have <host>:<dir>, e.g., `knuth.aeb.nl:/'. -For procfs, use `proc'. +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 -Instead of giving the device explicitly, one may indicate -the filesystem that is to be mounted by its UUID or -LABEL (cf. +Instead of a device name, LABEL=<label> or UUID=<uuid> may be given. +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. +(cf. .BR e2label (8) or -.BR xfs_admin (8)), -writing LABEL=<label> or UUID=<uuid>, -e.g., `LABEL=Boot' or `UUID=3e6be9de\%-8139\%-11d1\%-9106\%-a43f08d823a6'. +.BR xfs_admin (8)). +For example, `LABEL=Boot' or `UUID=3e6be9de\%-8139\%-11d1\%-9106\%-a43f08d823a6'. It's also possible to use PARTUUID= and PARTLABEL=. These partitions identifiers are supported for example for GUID Partition Table (GPT). @@ -86,7 +97,7 @@ See .BR blkid (8) or .BR lsblk (8) -for more details about devices identifiers. +for more details about device identifiers. .LP Note that @@ -106,9 +117,9 @@ contains spaces these can be escaped as `\\040'. .B The third field .RI ( fs_vfstype ). .RS -This field describes the type of the filesystem. Linux supports lots -of filesystem types, the most common are ext2, ext3, ext4, xfs, btrfs, vfat, -sysfs, proc, nfs and cifs. For more details, see +This field describes the type of the filesystem. Linux supports many +filesystem types, including ext4, xfs, btrfs, vfat, ntfs, hfsplus, +tmpfs, sysfs, proc, iso9660, udf, nfs, cifs, and many more. For more details, see .BR mount (8). An entry @@ -138,14 +149,19 @@ deprecated). .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 plus any additional options appropriate to the filesystem -type. For documentation on the available mount options, see -.BR mount (8). -For documentation on the available swap options, see +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 file system independent options are: +Basic filesystem independent options are: .TP .B defaults use default options: rw, suid, dev, exec, auto, nouser, and async. @@ -171,31 +187,26 @@ do not report errors for this device if it does not exist. .B The fifth field .RI ( fs_freq ). .RS -This field is used for these filesystems by the +This field is used by .BR dump (8) -command to determine which filesystems need to be dumped. If the fifth -field is not present, a value of zero is returned and -.B dump -will assume that the filesystem does not need to be dumped. +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 the +This field is used by .BR fsck (8) -program to determine the order in which filesystem checks are done at -reboot time. The root filesystem should be specified with a +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, and other filesystems should have a +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. If the sixth field is not present -or zero, a value of zero is returned and -.B fsck -will assume that the filesystem does not need to be checked. -.RE +parallelism available in the hardware. +Defaults to zero (don't fsck) if not present. .SH NOTES The proper way to read records from @@ -207,7 +218,7 @@ or The keyword .B ignore -as filesystem type (3rd field) is not more supported by the pure +as a filesystem type (3rd field) is no longer supported by the pure libmount based mount utility (since util-linux v2.22). .SH FILES -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
