From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756650Ab2EJG7e (ORCPT ); Thu, 10 May 2012 02:59:34 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:47316 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756148Ab2EJG7c (ORCPT ); Thu, 10 May 2012 02:59:32 -0400 X-AuditID: cbfee60d-b7b94ae000004ede-0f-4fab67536d40 Date: Thu, 10 May 2012 06:59:31 +0000 (GMT) From: AMIT SAHRAWAT Subject: =?windows-1252?Q?[Problem]NFS_Server_=96_Umount_results_in_Device_Busy.?= To: Trond.Myklebust@netapp.com Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, bfields@fieldses.org, "namjae.jeon@samsung.com" Reply-to: a.sahrawat@samsung.com MIME-version: 1.0 X-MTR: 20120510065727517@a.sahrawat Msgkey: 20120510065727517@a.sahrawat X-EPLocale: en_US.windows-1252 X-Priority: 3 X-EPWebmail-Msg-Type: personal X-EPWebmail-Reply-Demand: 0 X-EPApproval-Locale: X-EPHeader: ML X-EPTrCode: X-EPTrName: X-MLAttribute: X-RootMTR: 20120510065727517@a.sahrawat X-ParentMTR: Content-type: text/plain; charset=windows-1252 MIME-version: 1.0 Message-id: <32336989.330131336633170527.JavaMail.weblogic@epml01> X-Brightmail-Tracker: AAAAAA== X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id q4A733Sg008853 Linux Kernel: 2.6.35.14 We are using NFS for data transfer from one target to another target. On Server we are using 3 mount points to be used by application. And they are mentioned in /etc/exports When initially just NFS Server is started -We can mount and safely un-mount the NFS mount point. Now, when NFS client is started and we mount at the client. Without doing any IO if we do un-mount at the NFS Client it un-mounts safely. But when tried to un-mount the device at the NFS server it results in error Device Busy umount: can't umount /mnt: Device or resource busy Now , in order to umount the device - we have to kill the process nfsd and then it un-mounts easily. As per our understanding it should not be an issue with the un-mount when it is not being used and also there should be no dependency to kill nfsd to un-mount the device. It leads to problem of killing nfsd and restarting it to make other mount points work without issue. Is there any method to un-mount the device without getting this BUSY error? Or can we kill only nfsd service which was using that mount point? Please share your input on the solution to the above problem. Is this expected behavior? Thanks & Regards, Amit Sahrawat{.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I