From: Trond Myklebust Subject: Re: NFS Performance with sync or async Date: Sat, 28 May 2005 13:51:59 -0700 Message-ID: <1117313519.10746.20.camel@lade.trondhjem.org> References: <482A3FA0050D21419C269D13989C611308539BBA@lavender-fe.eng.netapp.com> <20050528125343.GY4944@inxservices.com> Mime-Version: 1.0 Content-Type: text/plain Cc: nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list2.sourceforge.net with esmtp (Exim 4.30) id 1Dc8I7-0006sU-E7 for nfs@lists.sourceforge.net; Sat, 28 May 2005 13:52:19 -0700 Received: from pat.uio.no ([129.240.130.16] ident=7411) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1Dc8I5-0007Lm-9d for nfs@lists.sourceforge.net; Sat, 28 May 2005 13:52:18 -0700 To: George Garvey In-Reply-To: <20050528125343.GY4944@inxservices.com> Sender: nfs-admin@lists.sourceforge.net Errors-To: nfs-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Post: List-Help: List-Subscribe: , List-Archive: lau den 28.05.2005 Klokka 05:53 (-0700) skreiv George Garvey: > On Fri, May 27, 2005 at 07:45:12PM -0700, Lever, Charles wrote: > > to clarify, you are using the "sync" mount option on your NFS clients? > Yes. > > why did you initially decide to use "sync"? > Reading urgings from some of the NFS authors ... Note that there are two "sync" options: one affects the server behaviour causing it to always make sure that the data reaches the disk if/when the client requests it (see 'man 5 exports') and the other affects the client (and is a mount option). You almost always want to set the "sync" option in /etc/exports (unless you really don't care about losing data if the server crashes and/or reboots). Are you sure that the urgings you mentioned above didn't concern this option? Conversely, you almost never want to set the sync mount option on the client. Any application that needs synchronous read/write behaviour and that doesn't want to use fcntl() or flock() locking will usually want to be rewritten to use the O_DIRECT mode for uncached file access. Cheers, Trond ------------------------------------------------------- This SF.Net email is sponsored by Yahoo. Introducing Yahoo! Search Developer Network - Create apps using Yahoo! Search APIs Find out how you can build Yahoo! directly into your own Applications - visit http://developer.yahoo.net/?fr=offad-ysdn-ostg-q22005 _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs