[Solved] Panther Pi SD Card read-only/corruption (.2 internal computer)


We’ve (Tim from RMIT) encountered a problem with the SD card on the Panther Raspberry pi (.2 internal computer) becoming corrupted/broken. The Micro SD card has been put into a “read-only” or “write-protected” state. (See outputs of fdisk below). I can’t do anything with the card, including mounting the card, re-flashing it through balenaEthcher (complains about the card being locked) or even erase the card.

This has happened with the original SD card last week. We replaced this with a brand-new SD card, and it happened again yesterday. I have read that there can be issues with powering off the Pi and the write-protection mode. (https://core-electronics.com.au/guides/read-only-raspberry-pi/)

This also seems to have coincided with us getting our Arm + Velodyne working. I doubt there are power issues here, but I thought it worth mentioning.

Any assistance would be greatly appreciated.

❯ sudo fdisk /dev/sdb2

Welcome to fdisk (util-linux 2.34).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

fdisk: cannot open /dev/sdb2: Read-only file system

❯ sudo hdparm -r0 /dev/sdb2                           

 setting readonly to 0 (off)
 readonly      =  1 (on)

Hi @Tim_RMIT,

The situation you describe shouldn’t happen, and we didn’t encounter it before. Double failure may indicate a deeper problem. We will do our best to investigate that issue.

  1. What model of card did you use as a replacement (Manufacturer, Model, Class, Capacity)?
  2. Do you have any intensive writes on RPi’s SD card in your software stack? If you are not sure, please run all your system configurations and check them using:
sudo apt-get install iotop
sudo iotop -o

Our team assumes two possible scenarios when extensive writing will happen:

  1. high swap memory utilization
  2. intensive logging to disk.

However, it still should last longer than a few days. Of course, we can send you a new SD card as a replacement. Please let me know how the test goes.

Best regards,

Hi @Hubert_Zwiercan ,

We’ll try out these elements. For the second crash, we have just been using the Husarion packages on the Pi and NUC (HP) (.2/.3) respectively for:

  • Only the existing husarion docker containers on .2
  • ur-docker on the NUC
  • velodyne-docker on the NUC

So I’m not sure if any of those would cause too many writes.

This issue only occurred after a reboot of the Pi.

The strange part for me is that, when I try to read the SD card on my Linux VM, I can see the system boot partiion, and read setting of the main partition through ldisk. But neither etcher or gparted will let me re-image or erase the card, saying the whole card is in read-only mode (or “locked” according to ethcher)

Also, the new SD card is a Samsung (160mbs write and I think 180mbs read).

Hi @Tim_RMIT,

I sent you a private message with a suggested solution. Please check it out.

Best regards,


Just for the public post I would note that we haven’t experienced this again, and did check the I/O read-writes, with nothing appearing to be an issue there.