Shawn,
Flow control is configured and these connections are all on the same 40g
subnet and all directly connected to the same switch.
I'm a little new with using lnet_selftest, but as I run it 1:1, I do see
the dropped packets go up on the client node pretty significantly when I
run it. The node I set for server does not drop any packets.
Brian Andrus
On 12/5/2017 9:20 AM, Shawn Hall wrote:
Hi Brian,
Do you have flow control configured on all ports that are on the
network path? Lustre has a tendency to cause packet losses in ways
that performance testing tools don’t because of the N to 1 packet
flows, so flow control is often necessary. Lnet_selftest should
replicate this behavior.
Is there a point in the network path where the link bandwidth changes
(e.g. 40 GbE down to 10 GbE, or 2x40 GbE down to 1x40 GbE)? That will
commonly be the biggest point of loss if flow control isn’t doing its job.
Shawn
On 12/5/17, 11:49 AM, "lustre-discuss on behalf of
jongwoo...@naver.com" <lustre-discuss-boun...@lists.lustre.org on
behalf of jongwoo...@naver.com> wrote:
Did you check your connection with iperf and iperf3 in TCP bandwidth?
in that case, these tools cannot find out packet drops.
Try checking out your block device backend responsibility with
benchmark tools like vdbench or bonnie++. Sometimes bad block device
causes incorrect data transfer.
-----Original Message-----
From: "Brian Andrus"<toomuc...@gmail.com>
To: "lustre-discuss@lists.lustre.org"<lustre-discuss@lists.lustre.org>;
Cc:
Sent: 2017-12-06 (수) 01:38:04
Subject: [lustre-discuss] lustre causing dropped packets
All,
I have a small setup I am testing (1 MGS, 2 OSS) that is connected via
40G ethernet.
I notice that when I run anything that writes to the lustre filesystem
causes dropped packets. Reads do not seem to cause this. I have also
tested the network (iperf, iperf3, general traffic) with no dropped
packets.
Is there something with writes that can cause dropped packets?
Brian Andrus
_______________________________________________
lustre-discuss mailing list
lustre-discuss@lists.lustre.org <mailto:lustre-discuss@lists.lustre.org>
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
_______________________________________________
lustre-discuss mailing list
lustre-discuss@lists.lustre.org <mailto:lustre-discuss@lists.lustre.org>
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
*Disclaimer*
This e-mail has been scanned for all viruses and malware, and may have
been automatically archived by Mimecast Ltd, an innovator in Software
as a Service (SaaS) for business.
_______________________________________________
lustre-discuss mailing list
lustre-discuss@lists.lustre.org
http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
