File System Read-Only Repair Guide

1 Overview

Introduces the background and scope of repairing a read-only file system.

1.1 Background

Some users may encounter an empty /etc/fstab file after an abrupt power loss and restart. /etc/fstab defines file systems automatically mounted at boot. When emptied, the file system becomes read-only and fails to mount automatically. Although the system may boot, ED-HMI series devices will display a blank screen. This guide provides detailed repair instructions.

1.2 Applicability

Applies to all ED-IPC and ED-HMI products.

2 Configuration Guide

The following steps use the ED-HMI3120-070C device as an example.

Preparation:

  • ED-HMI3120-070C boots successfully but displays a blank screen.

Steps:

  1. Execute the following command to check if /etc/fstab is empty.
cat /etc/fstab
  • If empty → Proceed to Step 2.
  • If ​not​ empty → Contact our technical support for troubleshooting.
  1. Remount the root directory with write permissions.
sudo mount -o remount,rw /
image-20250430143144841

TIP

If prompted, execute systemctl daemon-reload.

  1. Retrieve the device’s unique PARTUUIDs (partition identifiers).
sudo blkid
43613
  1. Open /etc/fstab and replace ​both​ existing PARTUUID entries with those from Step 3.
sudo nano  /etc/fstab

  1. Press Ctrl+O to save the file, then press Enter. Finally, press Ctrl+X to exit the editing mode.

  2. Reboot the device:

sudo reboot