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

# growfs(8)

expand an existing UFS file system

## NAME

**growfs** – expand an existing UFS file system

## SYNOPSIS

**growfs** \[**-Ny**\] \[**-s** *size*\] *special* \| *filesystem*

## DESCRIPTION

The **growfs** utility makes it possible to expand an UFS file system. Before running **growfs** the partition or slice containing the file system must be extended using [gpart(8)](/gpart/8.md). The **growfs** utility extends the size of the file system on the specified special file. The following options are available:

- **-N**

  “Test mode”. Causes the new file system parameters to be printed out without actually enlarging the file system.

- **-s** *size*

  Determines the *size* of the file system after enlarging in sectors. *Size* is the number of 512 byte sectors unless suffixed with a **b**, **k**, **m**, **g**, or **t** which denotes byte, kilobyte, megabyte, gigabyte and terabyte respectively. This value defaults to the size of the raw partition specified in *special* (in other words, **growfs** will enlarge the file system to the size of the entire partition).

- **-y**

  Causes **growfs** to assume yes as the answer to all operator questions.

## EXIT STATUS

Exit status is 0 on success, and \>= 1 on errors. Errors recoverable by user action are indicated by 2. OS errors, which are usually not recoverable, are indicated by 3 or greater.

## EXAMPLES

Expand root file system to fill up available space:

```
growfs /
```

Refresh the LUN size, resize the partition to use all available capacity, and expand the filesystem accordingly:

```
camcontrol reprobe da0
```

```
gpart recover da0
```

```
gpart resize -i 1 da0
```

```
growfs /dev/da0p1
```

## SEE ALSO

[growfs(7)](/growfs/7.md), [camcontrol(8)](/camcontrol/8.md), [fsck(8)](/fsck/8.md), [gpart(8)](/gpart/8.md), [newfs(8)](/newfs/8.md), [tunefs(8)](/tunefs/8.md)

## HISTORY

The **growfs** utility first appeared in FreeBSD 4.4. The ability to resize mounted file systems was added in FreeBSD 10.0.

## AUTHORS

Christoph Herrmann ⟨*chm@FreeBSD.org*⟩ Thomas-Henning von Kamptz ⟨*tomsoft@FreeBSD.org*⟩ The GROWFS team ⟨*growfs@Tomsoft.COM*⟩ Edward Tomasz Napierala ⟨*trasz@FreeBSD.org*⟩

## CAVEATS

When expanding a file system mounted read-write, any writes to that file system will be temporarily suspended until the expansion is finished.

## BUGS

Normally **growfs** writes cylinder group summary to disk and reads it again later for doing more updates. This read operation will provide unexpected data when using **-N**. Therefore, this part cannot really be simulated and will be skipped in test mode.