| # | |
| # SSD's and flash memory is available in a variety of different flavours. | |
| # As power drains from souch a system you stand to lose those bits! | |
| # | |
| # Firmware plays an important role in all of this. | |
| # | |
| # If your SSD is not powered up then the firmware will not be able | |
| # help you out. Most firmware is propriortary and as such, you can | |
| # power the drive up for a while (...?...) and hope for the best. | |
| # | |
| # The best approach is to use write cycles | |
| # delete the data and put it back. Then you will | |
| # have some level of certianty that the data has been | |
| # written again. | |
| # | |
| # Below are possible ways to mitigate or work around | |
| # the problem. Best idea is if it is important | |
| # have mulitple copies. | |
| # | |
| # Some quicker fixer-uper approaches, below | |
| # may prove useful in preserving your data. | |
| # | |
| # if your firmware behaves | |
| dd if=/dev/sdX of=/dev/null bs=2M | |
| # if your drive is offline | |
| dd if=/dev/sdX of=/dev/sdX bs=2M iflag=fullblock conv=sync,noerror status=progress | |
| # zfs scrub (software checksums) | |
| zpool scrub poolname | |
| # btrfs (software checksums) | |
| btrfs scrub start | |
| # If you just want to know if bits have flipped | |
| # then checksum your data. There are many | |
| # ways to checksum data on a file system | |
| # with a computer. | |
| # fingerprint | |
| https://github.com/ioquatix/fingerprint | |
| # gammar radition is problimatic and should be avoided | |
| # video links | |
| # error testing | |
| https://www.youtube.com/watch?v=rx3Y5x6uzKQ | |
| # how they are made | |
| https://www.youtube.com/watch?v=dX9CGRZwD-w |
3D NAND : about 1 year?
About 3 years? - MLC (Two bits per Cell) NAND flash memory
SLC Single-Level Cell