Recently, my UniFi Dream Wall (UDW) reported that storage was not healthy. Under Settings > System > Storage, it said:

“Drive failure detected” and “Storage not healthy” with an exclamation mark icon ⚠️

Here’s how I recovered a seemingly failed SD card in my UniFi Dream Wall without replacing it.

I had previously upgraded the internal SD card from the stock 512 GB to this SanDisk Extreme 2TB microSD card (or .de here), so I was surprised. It turns out the SD wasn’t broken, just filesystem was corrupted, likely due to a power outage or sudden reboot.

Symptoms

  • UniFi Protect stopped recording
  • Storage panel shows errors or degraded health
  • File I/O errors in logs
  • SSH access shows the SD card exists (lsblk), but is read-only or unusable
  • fsck refuses to run because the filesystem is in use

Root Cause

Linux filesystems like ext4 can get corrupted by unclean shutdowns. Especially with large-capacity SD cards (1–2 TB) and continuous write actions like the Unifi Protect which is constantly writing the recordings to the card, this may result in:

  • orphaned or multiply-claimed blocks
  • journal errors
  • missing or unreadable files (e.g. .ubv from UniFi Protect)

Step-by-Step Recovery

  1. SSH into the Dream Wall (if you don’t know how to do this, ask ChatGPT or look at the forums. You need a program called Putty, enable SSH access at the Dream Wall and login with username: root and the correct password).
  2. Identify the SD Card, type:lsblk
    Mine looked like this:
    sdq 1.9T
    ├─sdq1 4M
    └─sdq2 1.9T /sdcard1    You’re interested in /dev/sdq2.
  3. Stop Unifi Services
    • Stop the Unifi Protect (and if possible Unifi Network and other services, however, you might be connected via VPN) via the GUI
    • Type the following to also stop these:sudo systemctl stop ms
      sudo systemctl stop msr
      sudo systemctl stop msp
      sudo systemctl stop mst
  4. Unmount the SD Card
    umount /sdcard1
  5. Repair the Filesystem
    If the SD is cleanly unmounted, run a fast but full repair:
    sudo fsck -f -y -v /dev/sdq2
    (forces repair and automatically answers ‘yes’ to all prompts)In my case, I saw:

    root@My-Dreamwall:~# sudo fsck -cfv /dev/sdq2
    fsck from util-linux 2.36.1-dirty
    e2fsck 1.46.2 (28-Feb-2021)
    Checking for bad blocks (read-only test): ^C0.08% done, 2:00 elapsed. (2/0/0 errors)    Interrupted at block 413632
    /dev/sdq2: Updating bad block inode.

    /dev/sdq2: ***** FILE SYSTEM WAS MODIFIED *****
    root@My-Dreamwall:~# sudo fsck -y -f /dev/sdq2
    fsck from util-linux 2.36.1-dirty
    e2fsck 1.46.2 (28-Feb-2021)
    Pass 1: Checking inodes, blocks, and sizes

    Running additional passes to resolve blocks claimed by more than one inode…
    Pass 1B: Rescanning for multiply-claimed blocks
    Multiply-claimed block(s) in inode 92799604: 56602 125860
    Pass 1C: Scanning directories for inodes with multiply-claimed blocks
    Pass 1D: Reconciling multiply-claimed blocks
    (There are 1 inodes containing multiply-claimed blocks.)

    File /.srv/unifi-protect/video/2025/06/01/D021F993B06E_0_rotating_1748775448400.ubv (inode #92799604, mod time Sun Jun 1 13:25:56 2025)
    has 2 multiply-claimed block(s), shared with 1 file(s):
    (inode #1, mod time Fri Jul 4 22:52:03 2025)
    Clone multiply-claimed blocks? yes

  6. Do you want to recover any repaired files?
    Then temporarily mount the SD card:
    sudo mount /dev/sdq2 /mnt/temporary1

    Then check the lost+found directory and the specific repaired files/folders:
    ls -lah /mnt/temporary1/lost+found
    ls -lah "/mnt/temporary1/.srv/unifi-protect/video/2025/06/01/"

    You can safely remove the corrupt .ubv file(s):
    sudo rm "/mnt/temporary1/.srv/unifi-protect/video/2025/06/01/D021F993B06E_0_rotating_1748775448400.ubv"
    Now, unmount the temporary mount again:
    sudo umount /mnt/temporary17. Reboot the Dream Wall
    This will mount the SD card again and start all applications and processes.
    Check the storage and you will see something like this: