å 2010-12-01äç 01:07 +0800ïGregory Farnumåéï > On Mon, Nov 29, 2010 at 10:19 PM, Jeff Wu <cpwu@xxxxxxxxxxxxx> wrote: > > Is "40-50MB/s" the speed that it run bench at local btrfs disk ? > > not the speed that run bench from client to osd server ? > > with this speed ,run bench from client to osd server ,will which get > > about 20~25MB/s( 40~50MB /2 )speed ? > Data on Ceph is replicated across 2 OSDs (by default; this is > configurable). So while figuring out potential performance involves a > lot of variables, in a simple case like this where you aren't bounded > by network bandwidth you'll find that your read/write performance > simply tracks the slower disk. I'd expect your Ceph tests (at least > the streaming ones) to run at 40-50MB/s. Hi Greg,thank you very much for your quickly reply. > > Given that everything else is okay, I cannot stress enough that > running without a journal is going to cause significant performance > degradations. I have a hard time believing that it's responsible for > 13-second latencies, but it's possible. So how about you set up a > journal (it can just be a file or new partition on the drives you're > already using) and report back your results after you do that. :) I will add journal to ceph.conf to try it . > Adding a journal to the OSDs lets them turn all their random writes > into streaming ones. > -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
