For object storage I'm not sure there is a best each have their own advantages and disadvantages. If you need the space efficiency, then erasure is probably the best candidate. > -----Original Message----- > From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of > M Ranga Swami Reddy > Sent: 24 January 2016 16:09 > To: Nick Fisk <nick@xxxxxxxxxx> > Cc: ceph-users <ceph-users@xxxxxxxx> > Subject: Re: Performance - pool with erasure/replicated type > pool > > Thanks for details. > What is the best suitable pool type for object storage? > > Thanks > Swami > > On Sun, Jan 24, 2016 at 8:58 PM, Nick Fisk <nick@xxxxxxxxxx> wrote: > > Yes that seems about right. > > > > Erasure coding works similar to Raid5/6 so data will be striped, > > whereas replicated pools are simple copies of data. When you write to > > a 3x replicated pool you are having to write 3 times as much and so > > performance is lower. When writing to an erasure coded pool (k=8 m=2 > > for example) you are only having to write 20% worth of redundancy data. > > > > As for reads, in an ideal world both would have similar performance. > > But currently erasure coded pools require all chunks to be returned to > > satisfy a read request, even if the request is smaller than a whole > > object. Also the read request hits the primary OSD and then it > > forwards the remaining requests onto all the other OSD's which hold the > remaining erasure chunks. > > Another factor is that in erasure pools, as the object is split into > > smaller chunks you will be getting less performance from spinning > > disks as disks give the most bandwidth when doing 4MB+ IO's. > > > > All of these reasons tend to make reading slightly slower. > > > >> -----Original Message----- > >> From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf > >> Of M Ranga Swami Reddy > >> Sent: 24 January 2016 15:09 > >> To: ceph-users <ceph-users@xxxxxxxx> > >> Subject: Performance - pool with erasure/replicated type > >> pool > >> > >> Hello, > >> I have 2 pools as below: > >> > >> 1. pool1 with erasure type > >> 2. pool2 with replicated type > >> > >> I ran the "rados bench" with above 2 pool and the results came as below: > >> > >> - Read performance - around 60% better for replicated type pool ie > >> pool2 > >> - Write performance - around 50 % better for erasure type pool ie pool1. > >> > >> Can someone help me, if the above is correct behavior with ceph? > >> Or do I miss something here? > >> > >> Thanks > >> Swami > >> _______________________________________________ > >> 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 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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