My Raspberry Pi 3 Model B+ has been running with a “Samsung MicroSDHC 32GB PROFESSIONAL Plus UHS Speed Course 3 Class 10” for approximately one year without any problem. After that suddenly it stopped reacting and using any IO.
When I insert the particular SD card into my Windows PC, it just informs me the disk is damaged and needs to be formatted. I actually forwarded the SD card to a Linux Mint VM.
sudo ddrescue /dev/sdc ddrescue. img ddrescue. log
sudo dd if=/dev/sdc of=dd. img
md5sum < ddrescue. img
md5sum < dd. img
Both md5sum phone calls output the same hash and the ddrescue mapfile looks vacant, so this isn’t a hardware problem.
testdisk ddrescue. img
Testdisk finds out my (seemingly undamaged) boot partition and lists 21 additional ext4 partitions that will can’t be recovered.
Why a lot of? The whole space was as soon as filled with a single ext4 partition.
mke2fs -n ddrescue. img
fsck. ext4 ddrescue. img
fsck. ext4 -b 32768 ddrescue. img
fsck. ext4 -b 98304 ddrescue. img
fsck. ext4 -b 163840 ddrescue. img
fsck. ext4 -b 229376 ddrescue. img
fsck. ext4 -b 294912 ddrescue. img
fsck. ext4 -b 819200 ddrescue. img
fsck. ext4 -b 884736 ddrescue. img
fsck. ext4 -b 1605632 ddrescue. img
fsck. ext4 -b 2654208 ddrescue. img
fsck. ext4 -b 4096000 ddrescue. img
Thus none of these commands discovered the “real” ext4 partition. How do I find and recover it?
