(I've already reported this issue to centos and centos-devel. and waited long enough but didn't get any reply.) I'm evaluating dm-cache on CentOS 6 kernels 3.18.21-17.el6.x86_64 (Xen 4) and 2.6.32-573.7.1.el6.x86_64 (KVM). The test I do is a simple sequential read using dd(1). read_promote_adjustment and sequential_threshold have been set to 1 and 0, respectively. For the 2.6.32 kernel, all seems to be working fine, "#usedcacheblocks" correctly reflects the number of cached blocks based on what I'm reading with dd(1), performance is pretty much native SSD performance. However, the same test on the 3.18.21-17.el6.x86_64 kernel results in "#usedcacheblocks" being stuck to "2" and no performance improvement is observed. Any ideas what could be wrong? How can I further debug this? -- Thanos Makatos -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
