Bill Broadley wrote:
Sorry all, my math was a bit off (thanks Mike and others). To be clearer: * $24k or so per pair of servers and a pair of 15*750GB arrays * The pair has 16.4TB usable (without the normal 5% reserved by the filesystem) * The pair has 20.5TB raw (counting disks use for spare and redundancy) * Each pair has 22 TB marketing (Using TB = 10^9 instead of 2^30) So 7 servers could manage to provide the mentioned >= 100TB. Total cost of 7*$24k=$168k. Total storage cost does not include the GigE switches, 10G uplinks, nor 10G nics. Usable capacity of 7*16 = 112TB.
Ah, I see. That brings it down quite a bit. Thanks for clarifying.
The above config assumes that software RAID performance = hardware RAID performance or that the Dell MD-1000 can allow 2 masters access to all 15 disks (not at the same time). I'm not sure that either is true. From the scaling numbers I've seen published with PVFS2 and Lustre seems like it should still be possible to manage the mentioned goal of 1.5-2.5GB/sec (which assumes 220MB/sec or 440MB/sec per file server pair for 7 pairs.)
Again, if anyone can provide a real-world layout of what they are using, along with real-world speeds at the node, that would help out tremendously.
Thanks, Steve _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
