All, Seems like the high-level wrap-up of all this is: There are hopes that highly efficient SSDs will appear on the market that can leverage a passthru non-coalescing discard feature. And that a whitelist should be created to allow those SSDs to see discards intermixed with the rest of the data i/o. For the other known cases: SSDs that meet the ata-8 spec, but don't exceed it Enterprise SCSI mdraid with SSD storage used to build raid5 / raid6 arrays Non-coalescing is believed detrimental, but a regular flushing of the unused blocks/sectors via a tool like Mark Lord has written should be acceptable. Mark, I don't believe your tool really addresses the mdraid situation, do you agree. ie. Since your bypassing most of the block stack, mdraid has no way of snooping on / adjusting the discards you are sending out. Thus the 2 solutions that have been worked on already seem to address the needs of everything but mdraid. Also, there has been no discussion of dm based volumes. (ie LVM2 based volumes) For mdraid or dm it seems we need to enhance Mark's script to pass the trim commands through the full block stack. Mark, please cmiiw Greg -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
