Hi, we would like to build a gluster storage systems that combines our need for performance with our need for disaster recovery. I saw a couple of posts indicating that this is possible (http://gluster.org/pipermail/gluster-users/2010-February/003862.html) but am not 100% clear if that is possible Let's assume I have a total of 6 storage servers and bricks and want to spread them across 2 buildings for DR. server1-3 are in building1 server 4-6 are in building2. I create a distributed replicated volume and make sure that server1 replicates to server4, server2 to server5 and server3 to server6. I have this running today and it's working reasonably well. Now I have a couple of high performance compute systems in the server room of building 1 are currently using glusterfs to talk to the gluster storage cluster. Throughput is great, latency not so. I believe I have 2 options: 1. connecting server1,2,3 to my new IB switch (with rdma) and keep my compute servers connected via a tcp mount point /mnt/gluster. Latency will be reduced during normal operations. Gluster will figure out to use server1,2,3 because they can serve the files much quicker and will leave server4-6 for replication. If a server2 dies server4 will automatically take over serving files. Performance is reduced for many files but the end user does not experience and outage. Is this correct? 2. connecting server1,2,3 AND my compute systems to my new IB switch and mount storage via an rdma mount point /mnt/gluster-fast. End users will experience even lower latency. If server2 dies users will continue to be able to access files that were residing on the other 2 servers, however all files that were on server2 become unavailable and long running compute jobs might die. The end user needs to switch to tcp mount point /mnt/gluster to be able to access the files on server2 and other servers. Is this correct? Are my assumptions correct? Should I use 2 mount points to /mnt/gluster and /mnt/gluster-fast to give users the choice between very reliable and very performant? Thanks dipe
