RUT955 - JFFS2 Partition 100% Full - Overlayfs stuck in Read-Only - Recovery Mode Fails

Networking Solutions
1

Hi everyone,

I am facing a critical issue with a RUT955 (Firmware RUT9_R_00.07.04, Kernel 5.4.229). My device is stuck in Read-Only mode because the JFFS2 partition is completely saturated.

The symptoms:

  • SSH Login Message: “Your JFFS2-partition seems full and overlayfs is mounted read-only.”

  • df -h shows /overlay at 97% to 100% usage (3.7MB / 3.7MB).

  • Any configuration change is lost after reboot.

  • du -sk /overlay/upper/etc/config reports ~19MB, which is physically impossible for this partition, suggesting severe filesystem corruption or unlinked open files (ghost files).

What I have already tried (without success):

  1. Manual deletion via SSH: Tried rm -rf /overlay/upper/etc/config. It fails with: “rm: can’t remove […]: No space left on device” (JFFS2 cannot write the deletion marker).

  2. Firstboot command: Tried firstboot -y. It completes but the partition remains full and read-only after reboot.

  3. Hard Reset: Physical reset button does not clear the configuration.

  4. Bootloader Recovery Mode:

    • I can access the recovery page at 192.168.1.1/index.html.

    • I tried flashing several firmware versions (07.06, 07.03, and even Legacy 06.09.5).

    • The flash process seems to complete, but after the reboot, the router returns exactly to the same state: 100% full, same old config, and Read-Only.

It seems the flash memory (MTD6) is hardware-locked or the Bootloader fails to format the JFFS2 partition during the upgrade.

Questions:

  • Is there a specific .uboot or uboot.html procedure to force a low-level format of the flash?

  • Is this a known hardware failure where the NAND chip enters a permanent Read-Only state?

  • Any other CLI command to force-format the MTD6 partition?

Thanks for your help!

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2

Hello,

This would already indicate a flash-memory issue, which is considered a hardware issue and is usually dealt with via an RMA (repair or replacement). As your device is a RUT955, that would signal that the warranty is already due and is no longer valid.

In this case, I recommend replacing this device with a newer one, RUT956 for example, as this is not software-related.

Regards,
M.