On Fri, Jul 02, 2010 at 04:47:09PM -0400, Mike Snitzer wrote: > If a region doesn't support the discard > DM has no business processing anything related to the discard (barriers > included). It is as simple as that. Indeed - if an I/O is going to fail, discover that as early as we can, trying to avoid the relatively-expensive barrier process whenever we reasonably can. Alasdair -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel