Formatted SD Card Recovery – Small Change, Big Consequences
A reformat is a small change with big consequences. Whether you do it to a hard drive, an SSD, or an SD card, it tends to play out in the same way. There are only a relative handful of sectors or cells on a data storage device that govern how its filesystem behaves. A partition table on the “front” of the device tells the reader how many partitions to expect. SD cards and other small devices tend to have just one partition. Each partition is further defined by a superblock, which lays out the rest of the device’s architecture.
This SD card used FAT32, as do many small portable storage devices, since it is compatible with just about every computer operating system and has seen wide use for 20 years. The ground rules for this partition, what its directory structure looks like, and where its files live can all be found using the data in the superblock. When the SD card was accidentally reformatted, the old partition table and superblock for its FAT32 partition were completely overwritten.
When you reformat most devices, only the parts that govern the device’s architecture change. In most cases, everything else is left alone. Reformats can cause file corruption, and any data subsequently written to the device can overwrite the old data. But for the most part, the old data tends to be intact, especially if the user was prudent enough to immediately stop using the device.