---
name: "mount_ffs"
section: "8"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/mount_ffs"
---

# mount\_ffs(8)

mount a Berkeley Fast File System

## NAME

**mount\_ffs** – mount a Berkeley Fast File System

## SYNOPSIS

**mount\_ffs** \[**-o** *options*\] *special* *node*

## DESCRIPTION

The **mount\_ffs** command attaches the Berkeley Fast File System on the *special* device on to the file system tree at point *node*.

This command is invoked by [mount(8)](/mount/8.md) when using any of the following syntax:

**mount** \[options\] *special* *node*\
 **mount** \[options\] -t ffs *special* *node*\

The *special* device is either a [disklabel(8)](/disklabel/8.md) UID (DUID) or an entry in */dev*. If it is a DUID, it will be automatically mapped to the appropriate entry in */dev*. In either case the partition must be present in the disklabel loaded from the device. The partition name is the last letter in the entry name. For example, /dev/sd0a and 3eb7f9da875cb9ee.a both refer to the ‘a’ partition.

This command is normally executed per file system by [rc(8)](/rc/8.md) at boot time using the [mount(8)](/mount/8.md) command. The options are as follows:

- **-o** *options*

  Options are specified with a **-o** flag followed by a comma separated string of options. See the [mount(8)](/mount/8.md) man page for possible options and their meanings.

## SEE ALSO

[mount(2)](/mount/2.md), [disklabel(5)](/disklabel/5.md), [fstab(5)](/fstab/5.md), [disklabel(8)](/disklabel/8.md), [mount(8)](/mount/8.md), [umount(8)](/umount/8.md)

## HISTORY

A **mount\_ffs** command appeared in NetBSD 1.1.

## BUGS

It is possible for a corrupted file system to cause a crash.