Hi, Like I said, it's just my instinct. For a 180TB (raw) cluster you've got > some tough choices to make. Some options might include: > > 1) high density and low cost by just stick a bunch of 3GB drives in 5 2U > nodes and make sure you don't fill the cluster past ~75% (which you > probably don't want to do from a performance perspective anyway). Just > acknowledge that during failure/recovery there's going to be a ton of > traffic flying around between the remaining 4 nodes. > > 2) Lower density (1-2GB) drives and more 2U nodes for higher performance > but lower density and greater expense. > > 3) high eventual density and low eventual cost by buying 2U nodes that are > only partially filled with 3TB drives with the assumption that the cluster > is going to grow larger down the road. > > 4) 15 4-drive 1U nodes for less impact during recovery but greater expense > and lower density. > > All of these options have benefits and downsides. For production cluster > I'd want more than 5 nodes, but it wouldn't be the only consideration > (cost, density, performance, etc all would play a part).
To summarize, you recommend to focus on 2U servers, rather then 4U (HP, SuperMicro and so), and the best strategy seems to be start filling them with 3TB disks, spreading over the servers evenly. By the way, why 5 servers are so important? Why not 3 or 7 for the matter? Thanks again, Stas.
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