That's not necessarily the case with SSDs. When trim is enabled, the OS will tell the SSD that the data has been deleted. The controller will then erase the blocks at some point so they will be ready for new data to be written.

[–] zurohki@aussie.zone 13 points 5 days ago (1 children)

IIRC TRIM commands just tell the SSD that data isn't needed any more and it can erase that data when it gets around to it.

The SSD might not have actually erased the trimmed data yet. Makes it even more important to turn it off ASAP and send it away to a data recovery specialist if it's important data.

[–] hendrik@palaver.p3x.de 9 points 5 days ago* (last edited 5 days ago)

Yes. And best don't turn any setting off or change things around unless someone knows what they're doing. Power off the entire computer and unplug the storage device physically. (And subsequently, take it as an invitation to learn more about automated backups.)

[–] chunes@lemmy.world 1 points 5 days ago (1 children)

Why does anything need to be erased? Why not simply overwrite as needed?

[–] cmnybo@discuss.tchncs.de 4 points 5 days ago

It's not possible to overwrite data on flash memory. The entire block of flash has to be erased before anything can be written to it. Having the SSD controller automatically erase unused blocks improves the write speed quite a bit.