How to resizing the rootFS on R2S using fdisk?

Installing and Using OpenWrt
1

Hi everyone..

Tell me, please, if the way to use the cfdis utility to solve this problem?
Do not use the parted !
The OpenWRT script uses parted https://openwrt.org/docs/guide-user/advanced/expand_root, I would like to get
the same result using cfdisk or fdisk.

root@OpenWrt:~# df -Th
Filesystem           Type            Size      Used Available Use% Mounted on
/dev/root            ext4           58.9G     19.7M     58.8G   0% /
tmpfs                tmpfs         494.1M   1020.0K    493.1M   0% /tmp
tmpfs                tmpfs         512.0K         0    512.0K   0% /dev
2

No, it uses resizepart

There doesn't appear to be a fix argument nor an option not to prompt for user intervention. What are you trying to solve by not using parted?

3

With plenty of space available, why don't you just install the tools you need and call it a day?!

1 Like
4

Thanks for the answer.

Okay, but how to do the same, but using the programs: FDISK, GPARTED, GNOME DISKS.

That is, I want to do the same thing without using the script but manually. Where in the OpenWrt documentation can I see this or maybe an example of a user?

5

Can this example be used?

root@OpenWrt:~# [[fdisk /dev/sda]] 

Welcome to fdisk (util-linux 2.37.3).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

This disk is currently in use - repartitioning is probably a bad idea.
It's recommended to umount all file systems, and swapoff all swap
partitions on this disk.


Command (m for help): [[p]]

Disk /dev/sda: 59.63 GiB, 64023257088 bytes, 125045424 sectors
Disk model: ADATA_IM2S3134N-
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xc120d9f5

Device     Boot Start       End   Sectors  Size Id Type
/dev/sda1  *      512     33279     32768   16M 83 Linux
/dev/sda2       33792    246783    212992  104M 83 Linux

Command (m for help): [[d]]
Partition number (1,2, default 2): [[2]]

Partition 2 has been deleted.

Command (m for help): [[n]]
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): [[p]]
Partition number (2-4, default 2): [[2]]
First sector (33280-31277231, default 34816): [[33792]]
Last sector, +/-sectors or +/-size{K,M,G,T,P} 
    (33792-125045423, default 125045423): [[]]

Created a new partition 2 of type 'Linux' and of size 59.6 GiB.
Partition #2 contains a squashfs signature.

Do you want to remove the signature? [Y]es/[N]o: [[n]]

Command (m for help): [[w]]

The partition table has been altered.
Syncing disks.

root@OpenWrt:~#
6

I'm not feeling well today so I am not sure I remember correctly but I think your example is correct for growing the disk allocation for partition 2.

But...
That does not grow the filesystem. You need to run a different tool for that specific filesystem. For ext4, you could use resize2fs. You may need to run fsck before and after resizing. I think this is basic linux stuff not specific to OpenWrt. I think Gnome Disks can do it.

I don't have recent experience resizing a filesystem but It has worked fine for me in the past. Be sure to have your config settings, list of installed apps, scripts, user data and any other files you want to keep, backed up before making changes.

Note that the normal upgrade and installation of OpenWrt wipes out the resizing and will likely cause loss of data so plan accordingly on your next upgrade.

7

Thanks for your answer.

I wish you to recover and that your self -performance improves!

In my case, I consider the situation when my microSD card is empty on it only the OpenWRT operating system.

I would like to see a practical example to save it and use it in the future.

8

What issues are you having using gparted?

Just follow the graphics to resize, correct?

9

Yes, you're right, it can work, I'll create a new topic and show others how to do it.

10

When I came back here to post this I see that you presented a way to do it with gparted.

In the meantime, I logged a terminal session showing the resizing with cli tools. Actually, I flashed an sd card with an R4s ext4 firmware image and resized it on my linux pc and then put it in my R4S router and booted it for the first time. Maybe someone will find the steps useful.

## On linux PC ##
$ cd /tmp/r4s
$ ls
openwrt-24.10.0-952ead2bff08-rockchip-armv8-friendlyarm_nanopi-r4s-ext4-sysupgrade.img.gz
$ gunzip openwrt-24.10.0-952ead2bff08-rockchip-armv8-friendlyarm_nanopi-r4s-ext4-sysupgrade.img.gz 

gzip: openwrt-24.10.0-952ead2bff08-rockchip-armv8-friendlyarm_nanopi-r4s-ext4-sysupgrade.img.gz: decompression OK, trailing garbage ignored
$

$ lsblk -f
NAME                FSTYPE      FSVER    LABEL       UUID                                   FSAVAIL FSUSE% MOUNTPOINTS
sda
< redacted >...
$
$ sudo dd if="openwrt-24.10.0-952ead2bff08-rockchip-armv8-friendlyarm_nanopi-r4s-ext4-sysupgrade.img" of=/dev/sda bs=8096
21758+1 records in
21758+1 records out
176160768 bytes (176 MB, 168 MiB) copied, 7.75087 s, 22.7 MB/s
$
$ lsblk -f
NAME                FSTYPE      FSVER    LABEL       UUID                                   FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                                                        
├─sda1              ext4        1.0      kernel      84173db5-fa99-e35a-95c6-28613cc79ea9                  
└─sda2              ext4        1.0      rootfs      ff313567-e9f1-5a5d-9895-3ba130b4a864                
< redacted >...
$
$ sudo fdisk -l /dev/sda
Disk /dev/sda: 58.94 GiB, 63281561600 bytes, 123596800 sectors
Disk model: USB DISK        
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5452574f

Device     Boot  Start    End Sectors  Size Id Type
/dev/sda1  *     65536  98303   32768   16M 83 Linux
/dev/sda2       131072 344063  212992  104M 83 Linux
$
$# start = 131072  |  end = 15756064 (512 byte blocks) for about 8GB
$
$ sudo fdisk /dev/sda

Welcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help):d
Partition number (1,2, default 2): 2

Partition 2 has been deleted.

Command (m for help): n
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (2-4, default 2): 2
First sector (2048-123596799, default 2048): 131072
Last sector, +/-sectors or +/-size{K,M,G,T,P} (131072-123596799, default 123596799): 15756064

Created a new partition 2 of type 'Linux' and of size 7.5 GiB.
Partition #2 contains a ext4 signature.

Do you want to remove the signature? [Y]es/[N]o: N

Command (m for help): p

Disk /dev/sda: 58.94 GiB, 63281561600 bytes, 123596800 sectors
Disk model: USB DISK        
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5452574f

Device     Boot  Start      End  Sectors  Size Id Type
/dev/sda1  *     65536    98303    32768   16M 83 Linux
/dev/sda2       131072 15756064 15624993  7.5G 83 Linux

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

$
#
# Note new end and larger size for sda2
#
$ eject /dev/sda
 < remove and re-insert sd-card>
$
$ lsblk -f
NAME                FSTYPE      FSVER    LABEL       UUID                                   FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                                                        
├─sda1              ext4        1.0      kernel      84173db5-fa99-e35a-95c6-28613cc79ea9                  
└─sda2              ext4        1.0      rootfs      ff313567-e9f1-5a5d-9895-3ba130b4a864                  
< redacted >
$
$ sudo fsck /dev/sda2
fsck from util-linux 2.37.2
e2fsck 1.46.5 (30-Dec-2021)
rootfs: clean, 2221/6656 files, 14854/26624 blocks
$
$ 
# estimate of new size is 15624976 blocks or 7999987712 bytes. 1953112 in 8k blocks with a very small extra.
$
$ sudo resize2fs /dev/sda2 1953112
resize2fs 1.46.5 (30-Dec-2021)
Resizing the filesystem on /dev/sda2 to 1953112 (4k) blocks.
The filesystem on /dev/sda2 is now 1953112 (4k) blocks long.

$ sudo fsck /dev/sda2
fsck from util-linux 2.37.2
e2fsck 1.46.5 (30-Dec-2021)
rootfs: clean, 2221/399360 files, 39588/1953112 blocks
$ 
$ sudo eject /dev/sda
#
# Powered off R4S and swapped new sd-card in and cables as needed...
#
## On R4S router ##
#
$ ssh root@192.168.1.1
The authenticity of host '192.168.1.1 (192.168.1.1)' can't be established.
ED25519 key fingerprint is SHA256:Sq365p6uBxq+SvDpIBzxrHCaS8aJ5UIwTsp/r1LCr1V.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '192.168.1.1' (ED25519) to the list of known hosts.


BusyBox v1.36.1 (2025-02-08 21:33:11 UTC) built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt 24.10.0, r28427-6df0e3d02a
 -----------------------------------------------------
=== WARNING! =====================================
There is no root password defined on this device!
Use the "passwd" command to set up a new password
in order to prevent unauthorized SSH logins.
--------------------------------------------------
root@OpenWrt:~# df -Th
Filesystem           Type            Size      Used Available Use% Mounted on
/dev/root            ext4            7.4G     52.3M      7.3G   1% /
tmpfs                tmpfs           1.9G      1.2M      1.9G   0% /tmp
tmpfs                tmpfs         512.0K         0    512.0K   0% /dev
root@OpenWrt:~# poweroff
root@OpenWrt:~# Connection to 192.168.1.1 closed by remote host.
Connection to 192.168.1.1 closed.
$
1 Like
11

Thank you for taking the time to write this solution here! I am sure that this will be useful to many users!

12

What do you see as the use case for growing the root filesystem, especially to fill the available flash capacity, considering it gets wiped out on a regular upgrade.

I'm not sure I've heard of any way to retain data with recently added capabilities of owut or sysupgrade (asu) either. There may be better ways to use more storage for things like sharing files from the router or storing docker files or other data that will survive an upgrade.

Data files could be restored from backup after growing the filesystem, post upgrade, and backups are important to have anyway even if data files are stored someplace other than the root filesystem.

13

Thanks for your thoughts.

I have very few settings, so it’s not difficult for me to make them again after the update.

Or make a copy and restore it. But this is a worse than to have 104MB for programs ..

1 Like
14

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