From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail107.syd.optusnet.com.au (mail107.syd.optusnet.com.au [211.29.132.53]) by sourceware.org (Postfix) with ESMTP id E04BA39AF414 for ; Sat, 12 Jun 2021 01:32:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E04BA39AF414 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=optusnet.com.au Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=dimstar.local.net Received: from dimstar.local.net (n49-192-242-206.sun4.vic.optusnet.com.au [49.192.242.206]) by mail107.syd.optusnet.com.au (Postfix) with SMTP id BC28B102B5BC for ; Sat, 12 Jun 2021 11:32:20 +1000 (AEST) Received: (qmail 1486 invoked by uid 501); 12 Jun 2021 01:32:19 -0000 Date: Sat, 12 Jun 2021 11:32:19 +1000 From: Duncan Roe To: "cygwin@cygwin.com" Subject: Re: odd prob for cygwin 'dd' from a character device on network disk Message-ID: <20210612013219.GC14223@dimstar.local.net> Mail-Followup-To: "cygwin@cygwin.com" References: <60C168AF.4070400@tlinx.org> <20210610022303.GA14223@dimstar.local.net> <60C2D67E.3030407@tlinx.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <60C2D67E.3030407@tlinx.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=Tu+Yewfh c=1 sm=1 tr=0 a=r+VM+2qIvekI+VMePCMXTA==:117 a=r+VM+2qIvekI+VMePCMXTA==:17 a=kj9zAlcOel0A:10 a=r6YtysWOX24A:10 a=RSmzAf-M6YYA:10 a=O0FjA1KwLvPXi2hp_foA:9 a=CjuIK1q_8ugA:10 X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_05, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, SPF_FAIL, SPF_HELO_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Jun 2021 01:32:26 -0000 On Thu, Jun 10, 2021 at 08:20:30PM -0700, L A Walsh wrote: > On 2021/06/09 19:23, Duncan Roe wrote: > > > > > nfs / nodev? > > > I'm not sure what you mean or are asking. > I'm not using nfs...but cygwin. > > The file 'zero' is in the same dir as the file 'null'. > I usually read 'zero' and write to 'null, though > for 1-way testing, I read from file 'zero' on the remote > file system and write, locally to /dev/null. > > For other direction write to 'null' and read from > /dev/zero locally. > > When you said you were accessing zero over the network, you didn't say how so I suggested if you were using nfs then nodev might be the culprit. How are you accessing files aver the network? I suspect that whatever mechanism you are using has the equivalent of the nfs nodev feature (part of nfsmount, may be specified in fstab) and the nodev equivalent is turned on in your case.