Messages in this thread | | | Date | Wed, 9 Nov 2011 00:13:09 -0800 (PST) | From | Manavalan Krishnan <> | Subject | Re: Large file copy to NFS mounted directory causes delay in other application packets |
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(1) NFS is using TCP (2) yes eth0 is dedicated to heartbeat and eth1 is dedicated to NFS (3) I notice the following at the system where file copy is occuring
The kernel Recv-Q of the heartbeat application socket grows but not delivered to the socket recv call. Here is the netstat output.
Proto Recv-Q Send-Q Local Address Foreign Address
udp 11522 0 *:23435 *:*
As soon as I stop the file transfer, the socket recv call receives the packets and Recv-Q goes 0. (4) The server has 4 cpu cores and 25G RAM
________________________________ From: Eric Dumazet <eric.dumazet@gmail.com> To: Manavalan Krishnan <manavalan_k@yahoo.com> Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>; netdev <netdev@vger.kernel.org> Sent: Tuesday, November 8, 2011 10:24 PM Subject: Re: Large file copy to NFS mounted directory causes delay in other application packets
Le mardi 08 novembre 2011 à 21:28 -0800, Manavalan Krishnan a écrit : > Hi All > > I have two systems with two network interfaces each(eth0 and eth1). I > am running linux-HA (heartbeat deamon) on both the systems and they > use eth0 for exchanging heartbeats. I have NFS mounted directory in > one system and the NFS client uses the interface eth1. > > I try to copy a large file to NFS mounted directory. But the heartbeat > daemons misses the heartbeat packets from peers while copy is under > progress. I did tcpdump and found that the heartbeat packets are > delayed for few seconds before sent out on eth0. When I stop the file > copy, the heartbeats are delivered properly. It seems linux kernel > somehow giving priority for NFS packets(generated from the file copy) > over other application packets. > > Any thoughts on this behavior? Is there any way we can avoid this so > that application packets get equal chance while large file copy to NFS > mounted directory under progress? > CC netdev
1) Is your NFS using UDP or TCP ? 2) Is your eth0 dedicated to heartbeats and eth1 to NFS traffic ? 3) How do you know heartbeats are delayed ? 4) Is your server CPU bounded ?
Thanks
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