Thanks for the tips. Could anyone share their experience building a SSD pool or a SSD cache tier with HP SL4540 server? rgds, Sreenath On 4/2/15, Christian Balzer <chibi@xxxxxxx> wrote: > > Hello, > > On Wed, 1 Apr 2015 18:40:10 +0530 Sreenath BH wrote: > >> Hi all, >> >> we are considering building all SSD OSD servers for RBD pool. >> > I'd advise you to spend significant time reading the various threads in > this ML about SSD based pools. > Both about the current shortcomings and limitations of SSD pools and which > SSDs to (not) use. > >> Couple of questions: >> >> Does Ceph have any recommendation for number of cores/memory/ghz per >> SSD drive, similar to what is usually followed for hard drives(1 >> core/1 GB Ram/1Ghz speed)? >> > Note that that 1GHz core per OSD only applies with pure HDD OSDs, once a > journal SSD enters the picture you're likely to want 2-3 times that. > > You probably don't want to try this with anything less than the > upcoming Hammer release, but even with that the current rule for SSD based > pools is "the fastest cores you can afford and as many as possible". > And given the right loads, small write IOPS basically, you're probably > still going to be CPU bound. > > RAM is the same as with HDD based OSDs, but given how much more RAM helps > I would advise at least 2GB per OSD and as much as you can afford. > > Regards, > > Christian >> thanks, >> Sreenath >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > > > -- > Christian Balzer Network/Systems Engineer > chibi@xxxxxxx Global OnLine Japan/Fusion Communications > http://www.gol.com/ > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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