Expanding root partition and filesystem

Introduction

This instruction expands OpenWrt root partition and filesystem on x86 target.

Follow the automated section for quick setup.

Features

Support `ext4` and `squashfs` image types.
Automatically identify the root partition and filesystem.
Expand the root partition and filesystem using free space.
Preserve the scripts through firmware upgrade.
Automatically run after firmware upgrade.

Instructions

Configure startup scripts

cat /etc/uci-defaults/70-rootpt-resize if [ ! -e /etc/rootpt-resize ] \

 && type parted > /dev/null \
 && lock -n /var/lock/root-resize

then

 ROOT_BLK="$(readlink -f /sys/dev/block/"$(awk -e '$9=="/dev/root"{print $3}' /proc/self/mountinfo)")"
 ROOT_DISK="/dev/$(basename "${ROOT_BLK%/*}")"
 ROOT_PART="${ROOT_BLK##*[^0-9]}"
 parted -f -s "${ROOT_DISK}" \
   resizepart "${ROOT_PART}" 100%
 mount_root
 done
 touch /etc/rootpt-resize
 if [ -e /boot/cmdline.txt ]
 then
   NEW_UUID=`blkid ${ROOT_DISK}p${ROOT_PART} | sed -n 's/.*PARTUUID="\([^"]*\)".*/\1/p'`
   sed -i "s/PARTUUID=[^ ]*/PARTUUID=${NEW_UUID}/" /boot/cmdline.txt
 fi
 reboot

fi exit 1 EOF

cat /etc/uci-defaults/80-rootfs-resize if [ ! -e /etc/rootfs-resize ] \

 && [ -e /etc/rootpt-resize ] \
 && type losetup > /dev/null \
 && type resize2fs > /dev/null \
 && lock -n /var/lock/root-resize

then

 ROOT_BLK="$(readlink -f /sys/dev/block/"$(awk -e '$9=="/dev/root"{print $3}' /proc/self/mountinfo)")"
 ROOT_DEV="/dev/${ROOT_BLK##*/}"
 LOOP_DEV="$(awk -e '$5=="/overlay"{print $9}' /proc/self/mountinfo)"
 if [ -z "${LOOP_DEV}" ]
 then
   LOOP_DEV="$(losetup -f)"
   losetup "${LOOP_DEV}" "${ROOT_DEV}"
 fi
 resize2fs -f "${LOOP_DEV}"
 mount_root
 done
 touch /etc/rootfs-resize
 reboot

fi exit 1 EOF

cat > /etc/sysupgrade.conf /etc/uci-defaults/70-rootpt-resize /etc/uci-defaults/80-rootfs-resize EOF

Examples

Install packages

opkg update opkg install parted losetup resize2fs

Expand root partition/filesystem

sh /etc/uci-defaults/70-rootpt-resize

Automated

opkg update opkg install parted losetup resize2fs wget -U "" -O expand-root.sh "https://openwrt.org/_export/code/docs/guide-user/advanced/expand_root?codeblock=0" . ./expand-root.sh

Soruce: https://openwrt.org/docs/guide-user/advanced/expand_root