What are the exact parameters you are using? I often see people using dd in a way that effectively just measures write latency instead of throughput. Check out fio as a better/more realistic benchmarking tool.
Paul -- Paul Emmerich Looking for help with your Ceph cluster? Contact us at https://croit.io croit GmbH Freseniusstr. 31h 81247 München www.croit.io Tel: +49 89 1896585 90 Am Fr., 7. Dez. 2018 um 19:05 Uhr schrieb Scharfenberg, Buddy <[email protected]>: > > I'm measuring with dd writing from /dev/zero with a size of 1 MB 1000 times > to get client write speeds. > > -----Original Message----- > From: Paul Emmerich [mailto:[email protected]] > Sent: Friday, December 07, 2018 11:52 AM > To: Scharfenberg, Buddy <[email protected]> > Cc: Ceph Users <[email protected]> > Subject: Re: [ceph-users] Performance Problems > > How are you measuring the performance when using CephFS? > > Paul > > -- > Paul Emmerich > > Looking for help with your Ceph cluster? Contact us at https://croit.io > > croit GmbH > Freseniusstr. 31h > 81247 München > www.croit.io > Tel: +49 89 1896585 90 > > Am Fr., 7. Dez. 2018 um 18:34 Uhr schrieb Scharfenberg, Buddy > <[email protected]>: > > > > Hello all, > > > > > > > > I’m new to Ceph management, and we’re having some performance issues with a > > basic cluster we’ve set up. > > > > > > > > We have 3 nodes set up, 1 with several large drives, 1 with a handful of > > small ssds, and 1 with several nvme drives. We have 46 OSDs in total, a > > healthy FS being served out, and 1024 pgs split over metadata and data > > pools. I am having performance problems on the clients which I’ve been > > unable to nail down to the cluster itself and could use some guidance. I am > > seeing around 600MB/s out of each pool using rados bench, however I’m only > > seeing around 6MB/s direct transfer from clients using fuse and 30MB/s > > using the kernel client. I’ve asked over in IRC and have been told > > essentially that my performance will be tied to our lowest performing OSD > > speed / ( 2 * ${num_rep} ) and I have numbers which reflect that as my > > lowest performing disks are 180 MB/s according to osd bench and my writes > > are down around 30MB/s at best, with replication at 3. (180/(2*3)=30) > > > > > > > > What I was wondering is what, if anything I can do to get performance for > > the individual clients near at least the write performance of my slowest > > OSDs. Also given the constraints I have on most of my clients, how can I > > get better performance out of the ceph-fuse client? > > > > > > > > Thanks, > > > > Buddy. > > > > _______________________________________________ > > ceph-users mailing list > > [email protected] > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list [email protected] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
