---
name: "umount"
section: "8"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "openbsd", "macos"]
url: "https://new.carta.tech/umount"
---

# umount(8)

unmount file systems

## NAME

**umount** – unmount file systems

## SYNOPSIS

**umount** \[**-dfNnv**\] *special* *...* \| *node* *...* \| *fsid* *...*

**umount** **-a** \| **-A** \[**-F** *fstab*\] \[**-fnv**\] \[**-h** *host*\] \[**-t** *type*\]

## DESCRIPTION

The **umount** utility calls the [unmount(2)](/unmount/2.md) system call to remove a file system from the file system tree. The file system can be specified by its *special* device or remote node (*rhost*:*path*), the path to the mount point *node* or by the file system ID *fsid* as reported by “mount -v” when run by root.

The options are as follows:

- **-a**

  All the file systems described in [fstab(5)](/fstab/5.md) are unmounted.

- **-A**

  All the currently mounted file systems are unmounted, except for those mounted at */* or */dev*.

- **-d**

  If the filesystem is mounted on an [md(4)](/md/4.md) device (a memory disk), detach it after [unmount(2)](/unmount/2.md).

- **-F** *fstab*

  Specify the *fstab* file to use.

- **-f**

  The file system is forcibly unmounted. Active special devices continue to work, but all other files return errors if further accesses are attempted. The root file system cannot be forcibly unmounted. For NFS, a forced dismount can take up to 1 minute or more to complete against an unresponsive server and may throw away data not yet written to the server for this case. If a process, such as **umount** without the **-f** flag is hung on an NFS mount point, use the **-N** flag instead. Also, doing a forced dismount of an NFSv3 mount when [rpc.lockd(8)](/rpc.lockd/8.md) is running is unsafe and can result in a crash.

- **-h** *host*

  Only file systems mounted from the specified host will be unmounted. This option implies the **-A** option and, unless otherwise specified with the **-t** option, will only unmount NFS file systems.

- **-N**

  Do a forced dismount of an NFS mount point without checking the mount path. This option can only be used with the path to the mount point *node* and the path must be specified exactly as it was at mount time. This option is useful when a process is hung waiting for an unresponsive NFS server while holding a vnode lock on the mounted-on vnode, such that **umount** with the **-f** flag can't complete. Using this option can result in a loss of file updates that have not been flushed to the NFS server.

- **-n**

  Unless the **-f** is used, the **umount** will not unmount an active file system. It will, however, perform a flush. This flag disables this behaviour, preventing the flush if there are any files open.

- **-t** *type*

  Is used to indicate the actions should only be taken on file systems of the specified type. More than one type may be specified in a comma separated list. The list of file system types can be prefixed with “no” to specify the file system types for which action should *not* be taken. For example, the **umount** command:

  ```
  umount -a -t nfs,nullfs
  ```

  unmounts all file systems of the type NFS and NULLFS that are listed in the [fstab(5)](/fstab/5.md) file.

- **-v**

  Verbose, additional information is printed out as each file system is unmounted.

## ENVIRONMENT

- PATH\_FSTAB

  If the environment variable PATH\_FSTAB is set, all operations are performed against the specified file. PATH\_FSTAB will not be honored if the process environment or memory address space is considered “tainted”. (See [issetugid(2)](/issetugid/2.md) for more information.)

## FILES

- */etc/fstab*

  file system table

## SEE ALSO

[unmount(2)](/unmount/2.md), [fstab(5)](/fstab/5.md), [autounmountd(8)](/autounmountd/8.md), [mdconfig(8)](/mdconfig/8.md), [mount(8)](/mount/8.md)

## HISTORY

A **umount** utility appeared in Version 1 AT&T UNIX.