From: Trond Myklebust Subject: Re: Errors during a simple mount storm test Date: Thu, 04 Feb 2010 15:32:53 -0500 Message-ID: <1265315573.3317.50.camel@localhost> References: <4B6B2AE5.1070007@gluster.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: linux-nfs@vger.kernel.org To: Shehjar Tikoo Return-path: Received: from mail-out1.uio.no ([129.240.10.57]:46669 "EHLO mail-out1.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932905Ab0BDUc6 (ORCPT ); Thu, 4 Feb 2010 15:32:58 -0500 In-Reply-To: <4B6B2AE5.1070007-+FkPdpiNhgJBDgjK7y7TUQ@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, 2010-02-05 at 01:45 +0530, Shehjar Tikoo wrote: > Hi All > > The shell command below is probably not applicable to > all real world setups but I wanted to check it out nonetheless. > The problem is with the following command that is supposed > run a mount-umount loop: > > $ while [ true ]; do echo sending; mount localhost:/test -o > noacl,nolock,tcp,mountproto=tcp /mnt;umount /mnt; done > > For the first hundred iterations, it works fine but then starts > spewing errors with the mount command failing. For eg. > the output looks like below: > > sending > sending > sending > sending > sending > sending > sending > sending > sending > sending > sending > sending > mount.nfs: mount system call failed > umount: /mnt: not mounted > sending > mount.nfs: mount system call failed > umount: /mnt: not mounted > sending > mount.nfs: mount system call failed > umount: /mnt: not mounted > sending > mount.nfs: mount system call failed > umount: /mnt: not mounted > > Any ideas why the mount sequence stops abruptly? > There dont seem to be any relevant messages in the > dmesg output either. > > The client and server are on the same machine: > Linux indus 2.6.31-17-generic Ubuntu SMP x86_64 GNU/Linux > > I have verified through wireshark that the server is not > receiving any mount requests once the mount command start > failing. Instead there are only successful GETPORT requests > for the MOUNTv3 program. "netstat -t" will probably show you that all your free ports in the range 0-1023 are now in the TIME_WAIT state. This again means that you have to wait a couple of minutes for the TIME_WAITs to expire before you can try again. So basically, it is a case of your test being flawed. Trond