Mudi E750: Issues with mounting SD card

Technical Support for Routers
1

I have a Mudi E750.

I have inserted an sd card and I have scripts that store log files and other information to this card.

When I ssh onto the device, I see the mount as

/mnt/sda1

and I see my directory for storing things, call logs

so, if I do

ls /mnt/sd/logs

I see my files.

So, when I remove the SD card and put it into my computer, I do not see any of the files.

With the sd card still removed, I can still see the mount and my files.

What is going on here?

Any help to understand this and to also make sure I am writing to the SD card would be deeply appreciated.

2

How did you mount the SD card?
It looks like you did not mount it but created an directory called /mnt/sda1/ instead.

3

That is correct. I must have at some point mounted the sd card to develop my scripts because I DO have information on the SD card, it is just not current.

My assumption was/is that if the SD card is in the device, it is mounted.

My linux experience is limited to everything I have learned developing an application on the Mudi, so there are basic things I just do not know, but I am technical.

So, what should I do?

  1. Do I have to mount the SD card every time the device boots?
  2. If I do not mount the SD card and create a directory called /mnt/sda1/logs, does that now take precedent to the SD card?
  3. How can I determine if the directory I have created is on the device or on the SD card?

Thanks

4

I am not into linux so much, at least not into OpenWrt. But generally speaking:

Yes or you have to modify /etc/fstab for auto-mount.
https://openwrt.org/docs/guide-user/storage/usb-drives#automount_the_partition

A directory is entirely different from a mount point. If you do not mount the card, nothing will happen. You might write files into the directory, but they will not be transferred to the SD card - even if you mount it afterward.

If you later mount the SD card at /mnt/sda1 , the mount action will essentially “overlay” the SD card’s file system over the /mnt/sda1 directory. The original /mnt/sda1/logs directory (and its contents) you created will be hidden beneath the mount. It’s not deleted or overwritten, but it becomes inaccessible as long as the SD card is mounted at that path.

Usually, you will work with a temporary directory (like /home/user/blahblah) and then copy using rsync for example to the mount point as soon as it gets valid.

By using the right directory. :wink: