I have a Micro SD card here which I used with a Raspberry Pi, and I wanted to re-ISO it with a newly downloaded ISO from raspberry.org.
This is on Windows 7 Pro
In the Computer Management / Disk Management I see the card formatted as it was initially: 56 MB FAT, 3 GB ext4, 11.68 unallocated. It's a 16GB card, class 10 has HC I and an U with a 1 in it.
When I start Paragon's Linux File Systems for Windows I can browse the ext4-Partition and open it in Windows Explorer.
In Windows Explorer I also have access the 56 MB FAT partition.
I can create new files on that SD card, no error is thrown. Both on the FAT partition as well as the ext4 partition, thanks to "Linux File Systems for Windows".
When I take the card out of the reader and re-insert it, the new files are gone.
I have flashed 2018-06-27-raspbian-stretch-lite.img via Rufus as well as via Win32DiskImager. When I use a USB 3 reader, it writes the image at 60 Mb/s, with a normal USB 2 reader at 16 or so (can't remember, but below 20, it is a a reasonable value for USB 2, maybe even just 7).
On each of this flashings I receive a "Write successful" or "OK" message, and I was also able to see the USB reader's LED flash during the entire time.
Yet whenever I take the card out and reinsert it, it has all the original data on it, same partitions, same everything.
I also have deactivated Paragon's driver during flashing, to make sure it is not interfering.
I cannot format the FAT partition "Windows was unable to complete the format" and in the Disk Management Snap-In I cannot delete the ext4 volume (no message is shown)
This kind of stuff has never happened to me, so I'm at a loss. Any idea about what could be going on here?
diskpart shows the following result
DISKPART> attributes disk
Current Read-only State : No
Read-only : No
Boot Disk : No
Pagefile Disk : No
Hibernation File Disk : No
Crashdump Disk : No
Clustered Disk : No
Using diskpart to clean the card also does not work
Microsoft DiskPart version 6.1.7601
Copyright (C) 1999-2008 Microsoft Corporation.
DISKPART> list disks
Microsoft DiskPart version 6.1.7601
DISK - Display a list of disks. For example, LIST DISK.
PARTITION - Display a list of partitions on the selected disk.
For example, LIST PARTITION.
VOLUME - Display a list of volumes. For example, LIST VOLUME.
VDISK - Displays a list of virtual disks.
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 119 GB 0 B
...
Disk 10 Online 14 GB 11 GB
DISKPART> select disk 10
Disk 10 is now the selected disk.
DISKPART> list partition
Partition ### Type Size Offset
------------- ---------------- ------- -------
Partition 1 Primary 56 MB 4096 KB
Partition 0 Primary 3065 MB 60 MB
DISKPART> clean
DiskPart succeeded in cleaning the disk.
DISKPART> exit
Leaving DiskPart...
I can even see the LED flashing once when I press enter on the clean command.
Modifying contents of other cards (ie from another Raspberry Pi) does save the changes on that card, so it's not the system per se.
Maybe it's
Consumer SD cards can enter hardware read-only mode to save your data.
as mentioned in https://www.raspberrypi.org/forums/viewtopic.php?t=191393
But I really wonder why I don't get any errors when writing to it.
It's this card: https://www.amazon.de/gp/product/B0081WLJ7C
That card is rated at 20 MB/s and I just re-checked the write speed with Win32 Disk Imager, which effectively states 60 MB/s (a capital B). So probably the card is just damaged somehow.
