`dd if=/dev/zero of=/mnt/test/writetest bs=1M count=1000 oflag=dsync` -----Original Message----- From: Paul Emmerich [mailto:paul.emmerich@xxxxxxxx] Sent: Friday, December 07, 2018 12:31 PM To: Scharfenberg, Buddy <blspcy@xxxxxxx> Cc: Ceph Users <ceph-users@xxxxxxxxxxxxxx> Subject: Re: Performance Problems 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 <blspcy@xxxxxxx>: > > 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:paul.emmerich@xxxxxxxx] > Sent: Friday, December 07, 2018 11:52 AM > To: Scharfenberg, Buddy <blspcy@xxxxxxx> > Cc: Ceph Users <ceph-users@xxxxxxxxxxxxxx> > Subject: Re: 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 <blspcy@xxxxxxx>: > > > > 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 > > ceph-users@xxxxxxxxxxxxxx > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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