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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