The original post: /r/datahoarder by /u/JamesRitchey on 2025-07-30 17:17:43+00:00.
For fun, I decided to do a memory card test. I wrote data to a card, left it for little over a year, and then checked it for data loss. These are the details of the test, and the results.
Details:
- April 12, 2024 10:11PM the card was disconnected from power source (computer).
- July 30, 2025 9:45AM the card was reconnected to power source (computer), and re-checked for data loss.
- At no time between the disconnection date, and reconnection, was the card plugged into anything.
- The card used in this test was a SanDisk 4GB SDHC memory card. I've owned this card for many years, and used it for various things during that time span. While I've not had any issues in the past with data on the card, the card itself does have damage to the outer plastic from repeatedly being taken out of its storage case over the years.
- The card was stored in a clear plastic SD card case in my computer desk.
- The data used in this test was from "/dev/urandom" on Debian 12 AMD64 XFCE.
Results:
- Data verification was done using sha256sum for checksum comparison between the memory card, and an SHA-256 checksum made of it before. This test revealed matching checksums.
Original: 2c3e3395f8f75ee7e30c428f28ef7a411196d699ba0ff1e6a8dc1b31a61297e0
New: 2c3e3395f8f75ee7e30c428f28ef7a411196d699ba0ff1e6a8dc1b31a61297e0
- Data verification was done using cmp for byte-for-byte comparison between the memory card, and an exact image made of it before. This test revealed data was byte for byte identical.
sudo cmp "/dev/sdp" "sd.img" && echo $?
[sudo] password for user1:
0
Note:
- No analyses were done of the original data to determine its suitability for this sort of test.