From patchwork Thu Jul 14 02:26:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9228801 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 034766086B for ; Thu, 14 Jul 2016 02:27:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E5AD027D5D for ; Thu, 14 Jul 2016 02:27:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DA3F6280B0; Thu, 14 Jul 2016 02:27:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 58F9A27D5D for ; Thu, 14 Jul 2016 02:27:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751223AbcGNC1l (ORCPT ); Wed, 13 Jul 2016 22:27:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:57060 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149AbcGNC1j (ORCPT ); Wed, 13 Jul 2016 22:27:39 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 2DAD9AC5D; Thu, 14 Jul 2016 02:27:38 +0000 (UTC) From: NeilBrown To: Steve Dickson Date: Thu, 14 Jul 2016 12:26:43 +1000 Subject: [PATCH 1/8] nfs.man: clarify effect of 'retry' option. Cc: Linux NFS Mailing list Message-ID: <20160714022643.5874.60079.stgit@noble> In-Reply-To: <20160714021310.5874.22953.stgit@noble> References: <20160714021310.5874.22953.stgit@noble> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The total timeout for a "mount" attempt to a non-responsive server will always be a multiple of the time a single mount attempt in the kernel takes, which for TCP defaults to about 4 minutes. The documentation for the "retry" option seems to suggest that this can be used to set a maximum but it really sets a time after which to stop retrying. The total can be as much as "retry" plus the time for a single attempt. So clarify the documentation a bit, and also note that retrans defaults are different for UDP and TCP: #define NFS_DEF_UDP_RETRANS (3) #define NFS_DEF_TCP_RETRANS (2) Reported-by: Howard Guo Signed-off-by: NeilBrown --- utils/mount/nfs.man | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man index e541cdc95cb1..a0f790a5961b 100644 --- a/utils/mount/nfs.man +++ b/utils/mount/nfs.man @@ -158,8 +158,8 @@ up to a maximum timeout length of 60 seconds. The number of times the NFS client retries a request before it attempts further recovery action. If the .B retrans -option is not specified, the NFS client tries each request -three times. +option is not specified, the NFS client tries each UDP request +three times and each TCP request twice. .IP The NFS client generates a "server not responding" message after @@ -391,6 +391,16 @@ is 2 minutes, and the default value for background mounts is 10000 minutes If a value of zero is specified, the .BR mount (8) command exits immediately after the first failure. +.IP +Note that this only affects how many retries are made and doesn't +affect the delay caused by each retry. For UDP each retry takes the +time determined by the +.BR timeo +and +.BR retrans +options, which by default will be about 7 seconds. For TCP the +default is 3 minutes, but system TCP connection timeouts will +sometimes limit the timeout of each retransmission to around 2 minutes. .TP 1.5i .BI sec= flavors A colon-separated list of one or more security flavors to use for accessing