My data disks on two of my nodes are RAID-5, just because of circumstances. My other nodes are JBOD. I don't notice any real difference, but I haven't strongly benched it. Ian
On Mon, May 24, 2010 at 2:45 PM, Jonathan Ellis <jbel...@gmail.com> wrote: > I can think of at least 2 clusters running 32GB boxes with single > Cassandra processes on each. (16 seems to be more common.) At 64 I > would seriously consider multiple processes per machine. You'd want > to configure a Snitch such that same-machine boxes were considered the > same rack, there is no separate closeness level of same machine. > > At 32 I think you're fine with one process. Watch for latency spikes > and see how it goes. > > I would run raid 10 on the data disks if you can afford giving up the > space, otherwise raid0. I don't know that anyone's tested raid5. > > On Sun, May 23, 2010 at 3:30 PM, Aaron McCurry <amccu...@gmail.com> wrote: > > I am planning on setting up a Cassandra cluster on a small 16 node > cluster > > (possibly 32 way). Each machine has 8 cores 32 Gig of ram and 8 hds. My > > first thought is to setup one of those hds for the commit log, 6 for data > > and leave one for the OS. However I do have a concern about best > utilizing > > my memory, should I run a larger heap? Should I run several cassandra > > processes on the same box? > > My concern about the larger heap is because GC's typically get slower. > And > > if I run several procs, does cassandra realize that it's the same box for > > replication purposes? > > I do have other hd conf options, hardware RAID 0,1,or 5. > > Just looking for some general configuration options as well as some real > > world successes with similarly sized hardware. Thanks! > > Aaron > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of Riptano, the source for professional Cassandra support > http://riptano.com >
