Am 15.01.23 um 16:52 schrieb Reindl Harald:

quoted

to improve things, and actively supporting TRIM at the raid level is 
such an obvious advance ...

but that is NOT the topic of a question "What DOES TRIM/discard in RAID do"

DOES versus COULD DO

quoted

Whether it's worth the effort is a different question ... :-)

BTW:

in such implementations you have to consider

* re-add of devices
* file-systems with no trim-support
* raw-devcie usage like for "apache trafficserver"
* power-outage
* drive replacements

god beware pass a wrong discard reuqest to the underlying device

there are more important things like keep the idiotic 
"/sys/block/md0/md/mismatch_cnt" at 0 and until that isn't solveable 
after decades don't risk my data with advanced experiments

however, that's all not part of the topic "What does TRIM/discard in 
RAID do"