> On Nov 23, 2015, at 16:40, Z Zhang <zhangz.david@xxxxxxxxxxx> wrote: > > Hi Yan, Thanks for the reply. I already tried following settings, but no lock. client_readahead_min = 1048576 client_readahead_max_bytes = 4194304 Thanks. Zhi Zhang (David) > Subject: Re: Ceph-fuse single read limitation? > From: zyan@xxxxxxxxxx > Date: Mon, 23 Nov 2015 10:22:23 +0800 > CC: ceph-devel@xxxxxxxxxxxxxxx > To: zhangz.david@xxxxxxxxxxx > > >> On Nov 21, 2015, at 10:12, Z Zhang 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 can you check ceps-fuse log to see if readahead actually happen. Regards 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
