On Thu, 2009-08-20 at 10:38 -0400, Mark Lord wrote: > Would it still be okay to do the TRIMs when the entire parity stripe > (across all members) is being discarded? (As opposed to just partial > data there being dropped) Not really. The problem is that array verification is done at the block level not the fs level (although, I suppose, we could change that). So a fully discarded stripe still has to verify OK (as in what's read for the parity must match what's read for the data). All of this is the reason for the TPRZ bit for SCSI UNMAP ... and why WRITE_SAME is also under consideration for discards in T10. James -- 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