Mark Hahn wrote: >> So, maybe the bold question to ask would be: what would be the best RAID >> config for 3 HDDS and a max 6 node HPC cluster? Should I just use RAID 1 > > do you mean for each node?
No, the nodes are diskless. I plan to scale the cluster and 1TB of storage is quite enough, even if I use 6 nodes, or 2x6 nodes. That's actually what I know from my small experience in running CFD codes on 96 cores cluster. That's the reason for thinking about RAID in the first place: create stable and good performing centralized storage for the future number of the nodes (i.e. 12 nodes with 4 cores and 16 GB of RAM each). > >> for the system partitions on one disk, and RAID 0 for the simulation >> data placed on the same partitions on other two disks: after >> post-processing, the data is gone anyway... and with a good backup >> strategy, I don't have to worry about RAID0 not recovering from a disk >> fail... > > you're going to back up a raid0? >From your question, I sense it's a bad idea... :) I have no clue, this is the first time I'm doing this. > in any case, I think you should consider net-booting and using the node > disks as a 3x raid0. if the local files are really transient, then > your startup script can just reinitialize the local disks every boot. > (which would leave you with a working node even after a disk failure or two!) > that's assuming you need or can benefit from the capacity or bandwidth. > OK, I want a net boot because the nodes are diskless, the remaining question is how to use 3 HDDs with RAID to get a performance boost where I need it (like the /home where the data is written) and HA for the / dir., in case of disk fail. Is this the right way of thinking? >>> or better yet, don't bother booting of the local disk. simply make your >>> head/admin/master server reliable and net-boot. it's likley that nodes >>> won't be functional without the master server anyway, and net-booting >>> doesn't mean you can't use the local disk for swap/scratch/... >> Well, I want to configure the net boot for all diskless nodes and use >> the master node and it's RAID for a performance gains with writing CFD >> simulation data against network communication and to be able to scale >> more easily. > > I'm not sure I parse that. net booting is orthogonal to whether or not > you store data locally or over the net. but yes, gigabit is somewhat > slower than a single modern disk, so local IO will win. > Thanks. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
