> On Nov 21, 2015, at 10:12, Z Zhang <zhangz.david@xxxxxxxxxxx> wrote: > > Hi Guys, > > Now we have a very small cluster with 3 OSDs but using 40Gb NIC. We use ceph-fuse as cephfs client and enable readahead, but testing single reading a large file from cephfs via fio, dd or cp can only achieve ~70+MB/s, even if fio or dd's block size is set to 1MB or 4MB. > > From the ceph client log, we found each read request's size (ll_read) is limited to 128KB, which should be the limitation of kernel fuse's FUSE_MAX_PAGES_PER_REQ = 32. We may try to increase this value to see the performance difference, but are there other options we can try to increase single read performance? > try setting client_readahead_max_bytes to 4M Yan, Zheng -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
