From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Chudov Subject: NFS _write_ Performance became horrible overnight Date: Mon, 12 Jul 2010 10:37:48 -0500 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: linux-nfs@vger.kernel.org Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:50627 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751203Ab0GLPiK (ORCPT ); Mon, 12 Jul 2010 11:38:10 -0400 Received: by wwi17 with SMTP id 17so146858wwi.1 for ; Mon, 12 Jul 2010 08:38:09 -0700 (PDT) Sender: linux-nfs-owner@vger.kernel.org List-ID: Hello, I would like to apologize in advance if, for any reason, my question is inappropriate for this mailing list. Please let meknow if that is the case. This seems to be a very odd problem that I have isolated to NFS. I have two NFS servers. Server A and server B. They serve unrelated shares. Server A is actually two servers using DRBD to stay in sync. I also have a number of NFS clients. Both servers worked great up to about last night. Somehow, NFS writes became extremely slow over Server A, for all clients, but not for Server B. I have no idea, yet, what changed, but wanted to ask here if anyone ever had a similar problem (NFS performance going to shit overnight). Some data points: 1) From any client, reading files over NFS is fast 2) From any client, writing to NFS on Server A is VERY SLOW 3) From any client, writing to Samba shares on Server A is fast. 4) From any client, writing to NFS on Server B is fast. 5) When logged on to Server A, copying a file from local A filesystem to itself is fast. IOW, everything is fast, EXCEPT for NFS writes to server A. Any ideas what might cause this sudden deterioration of Server A? Thank you!!!!!!!!!!! i