Level wearing

What is level wearing?

• SSDs change data location to level the number of writing operations across all cells.

• if the location was always the same for changing dates, those cells would burn out quickly.

  • each cell stands ≈ 100 000 erasing cycles.

• firmware is responsible for doing the level wearing in an automated fashion.

• It also required a garbage collection system to identify freed sectors, that weren’t erased yet.

How does garbage collection work?

• it keeps a list of freed sectors.

• one block is erased only when all sectors are marked as free.

• even without a data connection, the garbage collection keeps running on its own and restarts in case of a power outage.