From owner-freebsd-current@FreeBSD.ORG Mon Jun 29 00:44:54 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0F319106566C for ; Mon, 29 Jun 2009 00:44:54 +0000 (UTC) (envelope-from nhoyle@hoyletech.com) Received: from mout.perfora.net (mout.perfora.net [74.208.4.194]) by mx1.freebsd.org (Postfix) with ESMTP id CF7A58FC08 for ; Mon, 29 Jun 2009 00:44:53 +0000 (UTC) (envelope-from nhoyle@hoyletech.com) Received: from [192.168.1.10] (pool-96-231-140-65.washdc.fios.verizon.net [96.231.140.65]) by mrelay.perfora.net (node=mrus1) with ESMTP (Nemesis) id 0MKpCa-1ML4n92qqC-000CHU; Sun, 28 Jun 2009 20:32:19 -0400 Message-ID: <4A480B8C.1060708@hoyletech.com> Date: Sun, 28 Jun 2009 20:32:12 -0400 From: Nathanael Hoyle User-Agent: Thunderbird 2.0.0.22 (Windows/20090605) MIME-Version: 1.0 To: Rick Macklem References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V01U2FsdGVkX19C1ctppmWifb7SoHsEFW3XglbxdKhFVYx+NCE ZowGOP4PcyJnGxQm5vjyVET45YZlyGps3ZIua2c6d8pdWlj1hK W+gzRSV3Gx1sc7Z0e9crhnFS367sNp7 X-Mailman-Approved-At: Mon, 29 Jun 2009 00:51:59 +0000 Cc: freebsd-fs@freebsd.org, freebsd-current@freebsd.org Subject: Re: umount -f implementation X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Jun 2009 00:44:54 -0000 Rick Macklem wrote: > I just noticed that when I do the following: > - start a large write to an NFS mounted fs > - network partition the server (unplug a net cable) > - do a "umount -f " on the machine > > that it gets stuck trying to write dirty blocks to the server. > > I had, in the past, assumed that a "umount -f" of an NFS mount would be > used to get rid of an NFS mount on an unresponsive server and that loss > of "writes in progress" would be expected to happen. > > Does that sound correct? (In other words, an I seeing a bug or a > feature?) > > Thanks in advance for any info, rick > ps: I have a simple "fix" if this is a bug, but I wanted to check before > submitting a patch. I think the answer is probably "it's a feature, not a bug", but that depends on your NFS mount options which you didn't give. I'd suggest you read up on NFS soft versus hard mounts. I think you're seeing the latter and expecting the former behavior. The first hit I found Googling seems pretty decent, though taken from Linux docs should still apply: http://tldp.org/HOWTO/NFS-HOWTO/client.html Under section 4.3.1 "Soft vs. Hard Mounting" there's a basic description. Best of luck, -Nathanael