On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon <agk@xxxxxxxxxx> wrote: > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: >> Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. >> Does it make sense? > > To stripe across devices with different characteristics? > > Some suggestions. > > Prepare 3 kernels. > O - Old kernel. > M - Old kernel with merge_bvec_fn disabled. How to disable it? Maybe just hack it as below? void blk_queue_merge_bvec(struct request_queue *q, merge_bvec_fn *mbfn) { //q->merge_bvec_fn = mbfn; } > N - New kernel. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel