Maybe you had an emuNAND and the primary partition is set to it. You could try getting emuNAND9 (can find it on github, and you can run the bin file as a Luma payload like Hourglass9) and format the card for no emuNAND. That might clear up your problems. If it doesn't, try testing it again and hopefully it will be able to test the whole card.
If I format the card for no emuNAND, will my files and downloaded games be lost?
Thank you.
But can't h2testw only test the unused blocks (because it does so by writing onto the SD card)? So if 20GB of that SD card is in use, it cannot test it? So .. did you actually use the program on an empty SD card?
You are right, only the available space can be tested, so it is testing whats left on the sd; sorry for the misunderstanding.
This was the result:
Warning: Only 12316 of 31967 MByte tested.
The media is likely to be defective.
20.1 MByte OK (41280 sectors)
12.0 GByte DATA LOST (25181888 sectors)
Details:0 KByte overwritten (0 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
12.0 GByte corrupted (25181888 sectors)
0 KByte aliased memory (0 sectors)
First error at offset: 0x0000000000000000
Expected: 0x0000000000000000
Found: 0xffffffffffffffff
H2testw version 1.3
Writing speed: 3.86 MByte/s
Reading speed: 2.39 MByte/s
H2testw v1.4
Thank you.