---
name: "growfs_postboot"
section: "7"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/growfs_postboot"
---

# growfs\_postboot(7)

automatically grow file systems during runtime

## NAME

**growfs\_postboot** – automatically grow file systems during runtime

## DESCRIPTION

The **growfs\_postboot** script expands filesystems automatically. Typically it is run via [devd(8)](/devd/8.md) in response to a SIZECHANGE notification. It will enlarge the final partition of a partitioned disk; expand a UFS file system; or expand a zpool device, as appropriate.

The following option in */etc/rc.conf* controls the behavior of **growfs\_postboot**:

- *growfs\_postboot\_enable*

  (“NO”) If set to “YES”, the script will enlarge partitions and file systems when disks expand.

Note that the [growfs(7)](/growfs/7.md) startup script will normally place a swap partition at the end of the disk containing the root file system, which will prevent the file system growing further; as such, in most cases it will be advisable to set *growfs\_swap\_size* to “0” in virtual machine images if **growfs\_postboot** is being enabled. If the system has already booted without that setting, a swap partition may have already been created, in which case it must be removed before this script can grow the root file system.

## FILES

- */etc/rc.conf*

  ## EXIT STATUS

The **growfs\_postboot** utility exits 0 on success, and \>0 if an error occurs.

## SEE ALSO

[rc.conf(5)](/rc.conf/5.md), [growfs(7)](/growfs/7.md), [devd(8)](/devd/8.md), [growfs(8)](/growfs/8.md), [zpool(8)](/zpool/8.md)

## HISTORY

The **growfs\_postboot** script first appeared in FreeBSD 16.0.

## AUTHORS

Colin Percival ⟨*cperciva@FreeBSD.org*⟩

## CAVEATS

I/O may be paused while file systems grow, so this functionality should be used with care on systems with strict latency requirements.