Resize OpenWRT partition

After OpenWrt installation on a 8GB sd card I noticed that I only had 104 MB of disk space left for future software installation. The file system was only using a fraction of the 8GB so I needed to expand the size of the partition as well as for the file system.

Boot up your openwrt device and perform the following steps from CLI.

First of all and just to be safe, remove all external disks attached.

Install software (preferably via Luci):

opkg lsblk parted resize2fs tune2fs

Now lets gather information about block devices:
lsblk
sda                   179:0    0 8G   0 disk   
├─sda1                179:1    0   16M   0 part
├─sda2               179:2    0   104M  0 part /  

Now lets enter to parted and Resize Partition

parted
p
Number  Start   End     Size    Type      File system  Flags
1      33.6M   50.3MB  16.8MB  primary   ext2         boot
2      67.1MB  104MB   104MB   primary

resizepart 2 8GB #Decide how much you want to expand according to sd card capacity
q

Resizing the file system

Remount root as read only:

mount -o remount,ro / 

Remove reserved GDT blocks:

tune2fs -O^resize_inode /dev/sda2

Fix part, answer yes to all. This will remove GDT blocks remnants.

fsck.ext4 /dev/sda2

Now reboot, log back in again and then resize the partition:

Expand root filesystem

resize2fs -f /dev/sda2

To apply changes, reboot  the system again and finish.

Sources

https://openwrt.org/docs/guide-user/installation/installation_methods/sd_card#fn

https://openwrt.org/docs/guide-user/installation/openwrt_x86#resizing_filesystem

https://openwrt.org/toh/friendlyarm/nanopi_r4s_v1#installation