On Tue, Aug 11 2015 at 1:36pm -0400, Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote: > >>>>> "Mike" == Mike Snitzer <snitzer@xxxxxxxxxx> writes: > > Mike> DM-thinp processes discards internally before it passes them down > Mike> (if configured to do so). If a discard is smaller than the > Mike> granularity of a thinp block (whose size is configurable) or if > Mike> the start and end of the discard's extent is misaligned (relative > Mike> to the thinp blocks mapped to the logical extent) then the discard > Mike> won't actually discard partial thinp blocks. > > That's fine. You can throw away anything you don't like as long as > discard_zeroes_data=0. Correct, dm-thinp sets discard_zeroes_data=0 > But I don't understand why having an artificial cap at 2GB fixes > things. Other than making it less likely for you to receive a runt by > virtue of being aligned to a power of two. That is the benefit. And when coupled with the new default max_discard of 64K (pending change from Jens for 4.3) this 2GB upper limit really isn't such a big deal. Unless I'm missing something... -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
