Mount

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Mount ( English mount , German  assemble, attach ) or hooking , integrate or activate designated for Unix and some other operating systems the process, a file system at a certain point - the mount ( English mount point ) - to be made available to allow the user to can access the files .

Unmount

The opposite of mounting is unmounting ( new German , English unmount ), dismounting ( English dismount ) or unmounting . This requires that no more processes access files on the file system and that all data is written to the file system. The operating system therefore tries to terminate all those processes in an orderly manner that still have open or unfinished accesses - if this cannot be achieved, the unmounting fails. If a program or process cannot release these resources because they are necessary for execution, a file system cannot therefore be unmounted: a prominent example of this is the system drive ( English boot volume ) of an operating system.

If a file system is removed without unmounting (e.g. a USB stick removed), data may be lost or the data integrity on the file system may be destroyed if not all data has yet been written to the file system.

The Unix command mount

Under Unix-like operating systems, mounting is initiated by calling up the command mount which, in the absence of command line parameters, outputs the list of activated file systems. Because of its proximity to the operating system, the syntax of the command is heavily dependent on the operating system and therefore differs from system to system, but it usually has the form

mount [optionen] device dir

device stands for a device file , for example /dev/cdrom, whereas dirthe last parameter specifies the mount point , i.e. H. an existing directory. Usually only the root account is allowed to perform mounts. However, if there are related entries in the fstab file, "normal" users can also mount corresponding devices, depending on the operating system. This is also possible with pmounta wrapper around mountit.

The analog command for unmounting a file system is umount and is usually with the syntax

umount dir_or_dev

called, where stands dir_or_devfor the device or the mount point.

Automated mounting

The integration is often done automatically without user intervention, especially when booting . Removable media such as CD , floppy disks or USB sticks , on the other hand, may be made available through access by an automounter.

With Windows , automounting is usually done automatically with the help of another drive letter such as D:or E:, while with macOS (formerly "Mac OS X" and "OS X") removable media are integrated by the automounter /Volumesand then appear on the desktop . A subdirectory of or is often used on Linux . /mnt/media

Examples

Under Unix-like operating systems (e.g. GNU / Linux ), the second partition on the primary hard drive is manually mounted at the first SCSI or SATA port with the following command:

$ mount /dev/sda2 /mein/verzeichnis

The directory must /mein/verzeichnisalready exist for this, the name is arbitrary. After hanging then the files and directories that are on that partition, under pathname as /mein/verzeichnis/entwürfe/blabla.txtusable. The files that were previously shown in /mein/verzeichnis(if it was not empty) are normally no longer accessible until they are unmounted.

Subsequent hanging is achieved by:

$ umount /dev/sda2

or

$ umount /mein/verzeichnis

A list of all activated file systems issues the following command:

$ mount

In addition to drives, storage that is not locally available can also be integrated. Examples are file systems such as NFS , xFS, and SHFS .

A file itself can also be integrated as a file system via the so-called " loop device "; this is most often used with ISO images :

$ mount -r -t iso9660 -o loop /pfad/zum/CD_oder_DVD-Abbild.iso /mein/verzeichnis

Web links

Individual evidence

  1. ↑ a b mounting under Linux. What does mounting mean? Retrieved September 29, 2015 .
  2. ↑ Thorsten Leemhuis: Please mount - automatically mount partitions and network shares. In: Heise online . November 16, 2013 . Retrieved September 29, 2015.
  3. ↑ Article in linuxwiki.de