Re: Performance Problems

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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
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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
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