> OK. > One last point : I tried the rr scheduler with default settings. > To unleash storage bandwidth, is it possible to set the round-robin or the > random scheduler to use a volume-based policy instead of a time-based policy > (that is, "switch to the other volumes every megabyte wrote" instead of > "switch to the other volume every 10 seconds") ? > If so, what is the lowest value I could use ? (If possible, I'd like to > test a 1MB round-robin or random sched). > the round robin and random schedule every create.. so every new file goes to the next node / random node. The 10 seconds is used to update the stats (which, in the case of random/rr only determines the min-disk-space check) Also, from a network point of view, a simple client/server setup did not > exceed 35MB/s with a bonnie++ test. (no options set to bonnie, just the > directory to use, and a GbE network) whereas a local test (server and client > on the same computer) shows a result of nearly 60MB/s. > What is the theorical overhead implied by GlusterFS ? > Can I expect to get something close to the theorical values (100MB/s for > the network connection limited by the 80MB/s of the FC RAID) or should ? > probably not with bonnie++, it was not written from network FS point of view. and our current focus is not really on getting good bonnie++ numbers, but towards scaling out (which is why you want a clustered filesystem) Using TCP transport and a raw, untuned setup, GlusterFS seems equal to NFS > (with the great advantage of storage aggregation for GlusterFS) > > Note : is it correct to say that "namespace" is like "metadata" ? (I'm > lost in what a namespace can be) > namespace is not 'metadata' in the regular sense. namespace is just a cache. if you lose glusterfs namespace, you lost nothing (it will rebuild on demand). if namespace were to be 'metadata', then losing namespace would make the rest of the nodes a big blob of 1s and 0s, and not files and folders. thanks, avati -- If I traveled to the end of the rainbow As Dame Fortune did intend, Murphy would be there to tell me The pot's at the other end.
