Deleting files from microSD card won't take

[Lopazopy]

I'm trying to delete some files from a microSD card that I use with my Fire Tablet, but the files are still there after I delete the files and remount the card.

Here are my steps:
1. In the tablet I eject the card before removing it
2. Mount the card on my Linux Mint machine (21.2 Cinnamon with kernel 5.15.0-91-generic)
3. Delete the files I no longer want
4. Empty Trash
5. The files no longer show in the folder
6. Remove and reinsert the card back into the computer
7. The files I deleted are there again

What is going on? Tried searching the forums for similar problems, but couldn't find anything.

[gittiest personITW]

Welcome to the forums.

Some SD/microSD cards have physical locks on them. A little switch on the side of it. Check that yours hasn't.
Let us know.

[Lopazopy]

It's a microSD card that I'm using with a USB card reader, so no switches.

Here are some things I've tried since my last post:
1. Tried a different USB card reader
2. I was able to finally get the PC to recognize the Fire tablet when plugged in with USB
3. Still unable to delete files when the microSD card is mounted through the tablet
4. Formatting the card didn't work
5. Sticking it into a Windows machine and had the same results
6. Used dd to write zeroes to the card and shred afterwards did nothing
7. Tried copying a small text file to the card that didn't take

I'm beginning to think this card is in some kind of permanent write lock or read only and I'm not sure if it's possible to get it out. I'll try any ideas you might have. Thanks!

[linux-rox]

6. Used dd to write zeroes to the card and shred afterwards did nothing

Let's try this again. With the card inserted but not mounted, run sudo dd if=/dev/zero of=/dev/sdx bs=1M count=10. Replace sdx with the correct device ID (e.g., sdb). Make damn sure you specify the correct one or you will be very sad. If not certain of the ID, take a look in Disks (an app on Menu). And notice you specify the device, not a partition on the device.

[Lopazopy]

The card was being mounted when I insert the USB reader, so I unmounted it first. Here are the steps with their output. No change after I re-mount the card.

Code: Select all

sudo umount /dev/sdb1

sudo dd if=/dev/zero of=/dev/sdb bs=1M count=10
10+0 records in
10+0 records out
10485760 bytes (10 MB, 10 MiB) copied, 0.736928 s, 14.2 MB/s

sudo shred -s $((2048*512)) -vzn0 /dev/sdb
shred: /dev/sdb: pass 1/1 (000000)...

Here are the results from sudo parted -l

Code: Select all

Model: Mass Storage Device (scsi)
Disk /dev/sdb: 15.9GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system  Flags
 1      4194kB  15.9GB  15.9GB  primary  fat32        lba

[linux-rox]

FWIW, I've never seen a drive able to ignore that dd wipe procedure. I'm inclined to think it's a hardware issue, but can't be certain.