a point you should understand (or already understand) any block is writeable, the garbage collector only mark if that block is empty or not empty block just need to be write one time non empty must be read merged and write (this take more time) so for speed empty block is faster, but non empty block is fast too... the other garbage colection function is know how many times block was write, to predict if it could use that block or a newer newer can have less problem of loss of information than old blocks, because ssd have limited write cicles that's the two main functions of trim... help garbage collection and 'block allocation' -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html