On 01/11/2011 10:44 AM, Nathan Stratton wrote: > On Mon, 10 Jan 2011, Joe Landman wrote: > >> Try this: >> >> # (on bravo) >> dd if=/dev/zero of=/cluster/shadow/big.file bs=1M count=20k >> >> This will write a 20GB file to the same partition. We need to see how >> fast that write is (outside of cache) >> >> Do the same test on the other machine. >> >> Infiniband won't make slow disks fast. So unless you are already >> getting a gigabyte or two per second (we do on our units), adding >> Infiniband won't get you any significant additional performance. >> >> Put another way, you are bound by the slowest aspect of your storage >> system. >> >> What are your underlying disks? Are these individual drives? RAID? >> What sort of RAID if it is a RAID? How is it organized? >> >> We tune our systems pretty hard, so we start with 2+GB/s for TB sized >> files before we ever touch the next stack up. Each additional stack >> you traverse takes performance away (you lose it in stack >> inefficiency). So you should start out with as fast a system as you >> possibly can, so you don't lose too much performance. > > What hardware gives you 2+GB/s? I am using the 16 port 3Ware 9750 cards > with fast drives and I dont get close to that. > Recent results here http://scalability.org/?p=2912 http://scalability.org/?p=2552 and older results http://scalability.org/?p=2356 Not a commercial. Follow the links in the .sig for more info. We've been a Gluster reseller/service provider for a while now (though for some reason we've not been on their site, and have asked them to work on that with us). -- Joseph Landman, Ph.D Founder and CEO Scalable Informatics Inc. email: landman at scalableinformatics.com web : http://scalableinformatics.com http://scalableinformatics.com/sicluster phone: +1 734 786 8423 x121 fax : +1 866 888 3112 cell : +1 734 612 4615
