Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
I would think that it is a huge benefit to do so. I don't have specific numbers for Gigabit ethernet yet (I need to build two crossover cables to do the test, but I do have some preliminary data using 10Gbps Infiniband. I used netperf to generate these numbers. ipoib, datagram mode (with an associated maximum MTU of 2044) standard tcp parameters: 2467 Mbps ipoib, connected mode (with an associated maximim MTU of 65520) standard tcp parameters: 5488 Mbps ipoib, connected mode (with an associated maximim MTU of 65520) modified tcp parameters: 7560 Mbps one way, 6226 Mbps in reverse ipoib, connected mode (with an associated maximim MTU of 65520) modified tcp parameters, after updating the outdated firmware on one node: 7862 Mbps both directions. Clearly, there are huge advantages to adjusting the MTU and send/receive buffers. While an MTU of 65520 is huge by ethernet standards, I only saw about a 3 to 5% reduction in performance with an MTU of 10000 BTW, my total expenditure for the point-to-point Infiniband link was US$184. On Sat, May 22, 2010 at 11:09 AM, Lee Riemer <lriemer at bestline.net> wrote: > Also, have people been enabling Jumbo frames and tweaking TCP Windows? > > > On 5/22/2010 3:00 AM, Phil Stricker wrote: > >> Hi! >> Am 22.05.2010 00:15, schrieb Matteo Tescione: >> >>> i've been using 802.3ad Dynamic link aggregation and been able to achieve >>> 1.3/1.4gbit with a dual gigabit intel port connected to a managed switch >>> (netgear). >>> >> sorry, but that is not possible for DRBD-replication. 802.3ad does just >> improve performance over 1GBit, if you transfer data to multiple hosts/mac >> adresses, because it does balance the streams via modulo operations of the >> mac adresses of both peers. As Ben Timby wrote, the one mode that provides >> multiple link aggregation for a single tcp stream is balance-rr. >> >> Phil >> _______________________________________________ >> drbd-user mailing list >> drbd-user at lists.linbit.com >> http://lists.linbit.com/mailman/listinfo/drbd-user >> > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user > -- Dr. Michael Iverson Director of Information Technology Hatteras Printing -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20100523/a65c4fcc/attachment.htm>