TP-Link Archer C20 v4 Snapshot - LuCI - Crashing when saving changes

Using latest snapshot built with imagebuilder, on day 12.07.2019., the router crashes when I click Save changes on any page, no matter the changes made. It recovers after 30 seconds when it rolls back the configuration. Otherwise works okay, but can't save any changes from LuCI. It works fine on 18.06.4.

Is it possible that the image is too big and there isn't enough space to save any config?

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Not really, generally it should save into RAM. I haven't checked the mounts, but the image is 5.5MB and the SPI Flash is 8MB.

Of course not! if it saves to RAM. RM is volatile and loses it's data when it loses power. Changes are made to overlay.

Run the following command form SSH, and see how much space you have free on overlay.


If you are to include the results here, please use the Pre-fomatted text tool </> for this purpose.

Okay, I will get back to you.

What I meant to say is that even if the overlay wasn't mounted, it should still save the settings, they just wouldn't persist across reboots. But it wouldn't freeze and rollback.

I don't know the of your overly partition. But if it's full and you try to save to it, that world throw an expecting that I don't know how it's handled.

Anyway next to check if there is space or not.

Okay, I'm not at home with the router right now. In any case, it is empty since it's been fresh installed

Sorry for being so late. I have checked, the overlay is mounted. Installing packages with opkg via CLI works, and they persist across reboots, as do changes to /etc/config/ made using a text editor. However, LuCI changes crash the device.

root@OpenWrt:~# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/root                 2048      2048         0 100% /rom
tmpfs                    29644      1340     28304   5% /tmp
tmpfs                    29644        36     29608   0% /tmp/root
tmpfs                      512         0       512   0% /dev
/dev/mtdblock4            4032      1072      2960  27% /overlay
overlayfs:/overlay        4032      1072      2960  27% /