FreeBSD manual
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GROWFS(7) FreeBSD Miscellaneous Information Manual GROWFS(7)
NAME
growfs, growfs_fstab - start up scripts to grow the root file system and
add swap
DESCRIPTION
The growfs script normally runs at the first boot after system
installation. If the boot disk is larger than the root file system and
boot partitions, and the root file system is in the last partition,
growfs can expand the root file system. It can also add a swap
partition, with a default size of 10% of the boot disk. Swap is limited
to twice the memory size up to 4 GB, 8 GB up to 8 GB of memory, and
memory size over 8 GB. It is also limited to the sysctl(8) value of
vm.swap_maxpages divided by 2. By default, no swap partition is created
if an existing swap partition is found or is listed in /etc/fstab, or the
disk is under 15 GB. The growfs_fstab script adds any new swap partition
to /etc/fstab after the root file system is made writable, and enables
its use as a dump partition if the dumpdev variable from rc.conf(5) is
set to AUTO.
The following options in /etc/rc.conf control the behavior of growfs:
growfs_enable ("NO") If set to "YES", the first time the
machine boots, the root file system will be
automatically expanded, if possible, to fill up
all available space after it, after optionally
adding a swap device at the end.
growfs_swap_size ("") If set to "0", the addition of a swap
partition is disabled. An empty value ("")
allows the creation of a swap partition with the
default size. If set to another value, the swap
partition will be created with the specified size
in bytes, even if another swap partition is
detected.
A setting for growfs_swap_size can be set in the kernel environment, in
which case it overrides the value from /etc/rc.conf.
To expand the root file system without rebooting, run the following
command:
% /etc/rc.d/growfs onestart
In addition, if a swap partition is added, run the command:
% /etc/rc.d/growfs_fstab onestart
Note that if a disk is expanded again, and if the root file system had
previously been expanded and a swap partition added, it is necessary to
delete the swap partition before this procedure in order to expand the
root file system to the new size. A new swap partition can be created
during the expansion.
IMPLEMENTATION NOTES
The growfs script only attempts to expand the root file system, and free
space must be available immediately after the root partition. It is
normally used on images that have a single file system. The script
requires that awk(1) be present and in the path. This usually means that
/usr must be available prior to running the script.
FILES
fstab(5), rc.conf(5), growfs(8), zpool(8)
HISTORY
The growfs manual page first appeared in FreeBSD 10.1. The ability to
add a swap partition was added in FreeBSD 14.0.
AUTHORS
The man page and script were written by John-Mark Gurney
<jmg@FreeBSD.org>. The ability to create a swap partition was added by
Michael Karels <karels@FreeBSD.org>.
FreeBSD 14.0-RELEASE-p11 November 22, 2022 FreeBSD 14.0-RELEASE-p11