Configuring extroot on GLiNet MT6000

Installing and Using OpenWrt
1

Hi eveyone.

I just purchased an MT6000 Flint 2 router which came with software:

OpenWrt 21.02-SNAPSHOT / LuCI openwrt-21.02 branch git-22.335.71649-0ecaf74, Kernel Version 5.4.238.

I am trying to configure extroot to use an external USB drive as overlay.
I followed the wiki tutorial on how to format the drive as ext4, copy the overlay folder to it, configure the /etc/config/fstab file to point to USB drive.

I tried many things, and it seems not to work. I have this in kernel logs:

[    3.646159] init: - preinit -
[    3.885138] mtk_soc_eth 15100000.ethernet eth0: configuring for fixed/2500base-x link mode
[    3.893471] mtk_soc_eth 15100000.ethernet eth0: Link is Up - 2.5Gbps/Full - flow control rx/tx
[    3.901286] mt7530 mdio-bus:1f lan1: configuring for phy/2500base-x link mode
[    3.910347] 8021q: adding VLAN 0 to HW filter on device lan1
[    7.969704] mount_root: loading kmods from internal overlay
[    7.982985] kmodloader: loading kernel modules from //etc/modules-boot.d/*
[    7.991040] kmodloader: done loading kernel modules from //etc/modules-boot.d/*
[    8.172553] block: attempting to load /etc/config/fstab
[    8.178784] block: unable to load configuration (fstab: Entry not found)
[    8.185487] block: no usable configuration
[    8.262935] F2FS-fs (loop0): Mounted with checkpoint version = 3b1d2a6d
[    8.270089] mount_root: loading kmods from internal overlay
[    8.282707] kmodloader: loading kernel modules from /tmp/overlay/upper/etc/modules-boot.d/*
[    8.291284] kmodloader: done loading kernel modules from /tmp/overlay/upper/etc/modules-boot.d/*
[    8.430146] block: attempting to load /etc/config/fstab
[    8.435405] block: unable to load configuration (fstab: Entry not found)
[    8.442112] block: no usable configuration
[    8.447010] mount_root: switching to f2fs overlay

block: unable to load configuration (fstab: Entry not found) - i have a feeling that during boot, it tries to read fstab from rom files (which does not exist -> /rom/etc/config/fstab) because original overlay (which contains fstab file with my configuration) is mounted after.

this is my fstab file configuration:

config global
	option anon_swap '0'
	option anon_mount '0'
	option auto_swap '1'
	option auto_mount '1'
	option delay_root '30'
	option check_fs '0'

config mount
	option uuid '45206cb6-ebc4-444d-a3d8-3b1e37f87640'
	option enabled '1'
	option fstype 'ext4'
	option options 'rw,noatime'
	option target '/overlay'

i tried to manually edit it, also using Luci interface, nothing works. i also tried to use device label "extroot" instead of uuid, i also tried to increase delay_root, use uci fstab.extroot="mount", doesn't work.

output of mount:

...
/dev/loop0 on /overlay type f2fs (rw,lazytime,noatime,background_gc=on,discard,no_heap,user_xattr,inline_xattr,inline_data,inline_dentry,flush_merge,extent_cache,mode=adaptive,active_logs=6,alloc_mode=reuse,fsync_mode=posix)
overlayfs:/overlay on / type overlay (rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work)
....
/dev/sda1 on /tmp/mountd/disk1_part1 type ext4 (rw,relatime)

output of block info:

/dev/sda1: UUID="45206cb6-ebc4-444d-a3d8-3b1e37f87640" LABEL="extroot" VERSION="1.0" MOUNT="/tmp/mountd/disk1_part1" TYPE="ext4"

i found this topic on OpenWrt where other users are complaining about this behaviour:

my question is if anyone has managed to make this work on MT6000 with stock or custom firmware?

Thank you!

2

You have to ask at the GL.iNET forum as you are using their software.

2 Likes
3

... or install proper openwrt.

It appears you are using firmware that is not from the official OpenWrt project.

When using forks/offshoots/vendor-specific builds that are "based on OpenWrt", there may be many differences compared to the official versions (hosted by OpenWrt.org). Some of these customizations may fundamentally change the way that OpenWrt works. You might need help from people with specific/specialized knowledge about the firmware you are using, so it is possible that advice you get here may not be useful.

You may find that the best options are:

  1. Install an official version of OpenWrt, if your device is supported (see https://firmware-selector.openwrt.org).
  2. Ask for help from the maintainer(s) or user community of the specific firmware that you are using.
  3. Provide the source code for the firmware so that users on this forum can understand how your firmware works (OpenWrt forum users are volunteers, so somebody might look at the code if they have time and are interested in your issue).

If you believe that this specific issue is common to generic/official OpenWrt and/or the maintainers of your build have indicated as such, please feel free to clarify.

3 Likes
4

I understand that there might be differences between shipped software and OpenWrt ones.
This post is also abot finding out if anyone managed to create extroot on MT6000 using either shipped/officilal/modified version of OpenWrt. Or, if someone has any idea abot this.
This would help me decide if I should try to investigate further or not.

5

That's why we can't answer the question, their firmware is a black box.

As @egc pointed out, post at their forum.

There's no issue doing the same using the vanilla openwrt image from openwrt.org.

2 Likes
6

Just flash the sysupgrade to OpenWrt 24.10.5 and you will be fine. Follow the well written guide. Then ask on here if you get stuck.

1 Like