8.2. Creating the /etc/fstab File

The /etc/fstab file is used by some programs to determine where file systems are to be mounted by default, in which order, and which must be checked (for integrity errors) prior to mounting. Create a new file systems table like this:

cat > /etc/fstab << "EOF"
# Begin /etc/fstab

# file system  mount-point  type   options         dump  fsck
#                                                        order

/dev/<xxx>     /            <fff>  defaults        1     1
/dev/<yyy>     swap         swap   pri=1           0     0
proc           /proc        proc   defaults        0     0
sysfs          /sys         sysfs  defaults        0     0
tmpfs          /dev/shm     tmpfs  defaults        0     0
# End /etc/fstab

Replace <xxx>, <yyy>, and <fff> with the values appropriate for the system, for example, hda2, hda5, and ext3. For details on the six fields in this file, see man 5 fstab.

The /dev/shm mount point for tmpfs is included to allow enabling POSIX-shared memory. The kernel must have the required support built into it for this to work (more about this is in the next section). Please note that very little software currently uses POSIX-shared memory. Therefore, consider the /dev/shm mount point optional. For more information, see Documentation/filesystems/tmpfs.txt in the kernel source tree.

Filesystems with MS-DOS or Windows origin (i.e.: vfat, ntfs, smbfs, cifs, iso9660, udf) need the “iocharset” mount option in order for non-ASCII characters in file names to be interpreted properly. The value of this option should be the same as the character set of your locale, adjusted in such a way that the kernel understands it. This works if the relevant character set definition (found under File systems -> Native Language Support) has been compiled into the kernel or built as a module. The “codepage” option is also needed for vfat and smbfs filesystems. It should be set to the codepage number used under MS-DOS in your country. E.g., in order to mount USB flash drives, a ru_RU.KOI8-R user would need the following in the options portion of its mount line in /etc/fstab:


The corresponding options fragment for ru_RU.UTF-8 users is:



In the latter case, the kernel emits the following message:

FAT: utf8 is not a recommended IO charset for FAT filesystems,
    filesystem will be case sensitive!

This negative recommendation should be ignored, since all other values of the “iocharset” option result in wrong display of filenames in UTF-8 locales.

It is also possible to specify default codepage and iocharset values for some filesystems during kernel configuration. The relevant parameters are named “Default NLS Option” (CONFIG_NLS_DEFAULT), “Default Remote NLS Option” (CONFIG_SMB_NLS_DEFAULT), “Default codepage for FAT” (CONFIG_FAT_DEFAULT_CODEPAGE), and “Default iocharset for FAT” (CONFIG_FAT_DEFAULT_IOCHARSET). There is no way to specify these settings for the ntfs filesystem at kernel compilation time.

It is possible to make the ext3 filesystem reliable across power failures for some hard disk types. To do this, add the barrier=1 mount option to the appropriate entry in /etc/fstab. To check if the disk drive supports this option, run hdparm on the applicable disk drive. For example, if:

hdparm -I /dev/sda | grep NCQ

returns non-empty output, the option is supported.

Note: Logical Volume Management (LVM) based partitions cannot use the barrier option.