From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Riemer Subject: Re: tune ib stack Date: Tue, 09 Apr 2013 13:43:48 +0200 Message-ID: <5163FEF4.1000507@profitbricks.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Vasiliy Tolstov Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 09.04.2013 13:12, Vasiliy Tolstov wrote: > Hello. I have some servers, with mellanox ConnectX-3 and have some questions: > Why max_mtu differs with active_mtu? Because 2048 is the default and 4096 is the max. supported MTU by the hardware. > How can i set active mtu? Something like this: echo 4096 > /sys/class/infiniband/mlx4_0/device/mlx4_port1_mtu > Why ibstatus says that i have only 10 Gb/s ? Could be a bug. Which OFED/Kernel (if using in-tree IB modules) do you use? Mine says with ConnectX2 QDR: "40 Gb/sec (4X QDR)" > All cables support 40 Gb/s. > > Thanks for any help. > > Linux xen28 3.8.6-1-xen #1 SMP Fri Apr 5 18:48:02 UTC 2013 (713918b) > x86_64 x86_64 x86_64 GNU/Linux > > Infiniband device 'mlx4_0' port 1 status: > default gid: fe80:0000:0000:0000:0025:90ff:ff17:9b25 > base lid: 0x34 > sm lid: 0x4 > state: 4: ACTIVE > phys state: 5: LinkUp > rate: 10 Gb/sec (4X) > link_layer: InfiniBand You should see "40 Gb/sec (4X QDR)" here. Perhaps the OFED is too old so that FDR and ConnectX 3 aren't supported, yet. "10 Gb/sec (4X)" seems to be the default case if a rate isn't supported. Cheers, Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html