.\"
.\" Copyright 2026 Colin Percival
.\"
.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.Dd July 31, 2026
.Dt GROWFS_POSTBOOT 7
.Os
.Sh NAME
.Nm growfs_postboot
.Nd automatically grow file systems during runtime
.Sh DESCRIPTION
The
.Nm
script expands filesystems automatically.
Typically it is run via
.Xr devd 8
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.
.Pp
The following option in
.Pa /etc/rc.conf
controls the behavior of
.Nm :
.Bl -tag -width "growfs_postboot_enable" -offset indent
.It Va growfs_postboot_enable
.Pq Dq Li NO
If set to
.Dq Li YES ,
the script will enlarge partitions and file systems when disks expand.
.El
.Pp
Note that the
.Xr growfs 7
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
.Va growfs_swap_size
to
.Dq Li 0
in virtual machine images if
.Nm
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.
.Sh FILES
.Bl -tag -compact -width Pa
.It Pa /etc/rc.conf
.El
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr rc.conf 5 ,
.Xr growfs 7 ,
.Xr devd 8 ,
.Xr growfs 8 ,
.Xr zpool 8
.Sh HISTORY
The
.Nm
script first appeared in
.Fx 16.0 .
.Sh AUTHORS
.An Colin Percival Aq Mt cperciva@FreeBSD.org
.Sh CAVEATS
I/O may be paused while file systems grow, so this functionality should be used
with care on systems with strict latency requirements.