How can I check the health of my micro SD cards?

I've been using HDDGuru's Low-Level Format tool for ages. When a flash drive starts acting weird, I do a full low-level format. If I see sector errors, it means the drive's bad. If not, it’s a clean slate ready for use.

I personally have a couple of methods for testing my SD and USB drives. First, calculate how many sectors the flash should have based on its capacity. Then, wipe it clean by writing zeroes using a tool like `dd`. Afterward, see how much you wrote back compared to the expected amount—if there's a discrepancy, it indicates bad sectors. The second method is to create a random 1MB file and copy it multiple times; then compare MD5 checksums to ensure everything matches.

You can check the health of your SD card using HDD Sentinel, which has a guide for monitoring SD card status. If your card doesn't support S.M.A.R.T., you could try H2testw to run a full check. Just keep in mind, if it starts going read-only, it means the card has failed.

It's a common misconception to replace SD cards every year. As long as you're keeping an eye on their performance and doing checks as needed, you don't have to toss them on a strict schedule!