1.\" 2.\" Copyright 2026 Colin Percival 3.\" 4.\" SPDX-License-Identifier: BSD-2-Clause 5.\" 6.Dd July 31, 2026 7.Dt GROWFS_POSTBOOT 7 8.Os 9.Sh NAME 10.Nm growfs_postboot 11.Nd automatically grow file systems during runtime 12.Sh DESCRIPTION 13The 14.Nm 15script expands filesystems automatically. 16Typically it is run via 17.Xr devd 8 18in response to a SIZECHANGE notification. 19It will enlarge the final partition of a partitioned disk; expand a UFS 20file system; or expand a zpool device, as appropriate. 21.Pp 22The following option in 23.Pa /etc/rc.conf 24controls the behavior of 25.Nm : 26.Bl -tag -width "growfs_postboot_enable" -offset indent 27.It Va growfs_postboot_enable 28.Pq Dq Li NO 29If set to 30.Dq Li YES , 31the script will enlarge partitions and file systems when disks expand. 32.El 33.Pp 34Note that the 35.Xr growfs 7 36startup script will normally place a swap partition at the end of the disk 37containing the root file system, which will prevent the file system growing 38further; as such, in most cases it will be advisable to set 39.Va growfs_swap_size 40to 41.Dq Li 0 42in virtual machine images if 43.Nm 44is being enabled. 45If the system has already booted without that setting, a swap partition may 46have already been created, in which case it must be removed before this script 47can grow the root file system. 48.Sh FILES 49.Bl -tag -compact -width Pa 50.It Pa /etc/rc.conf 51.El 52.Sh EXIT STATUS 53.Ex -std 54.Sh SEE ALSO 55.Xr rc.conf 5 , 56.Xr growfs 7 , 57.Xr devd 8 , 58.Xr growfs 8 , 59.Xr zpool 8 60.Sh HISTORY 61The 62.Nm 63script first appeared in 64.Fx 16.0 . 65.Sh AUTHORS 66.An Colin Percival Aq Mt cperciva@FreeBSD.org 67.Sh CAVEATS 68I/O may be paused while file systems grow, so this functionality should be used 69with care on systems with strict latency requirements. 70