From owner-freebsd-questions@FreeBSD.ORG Sun May 1 12:39:08 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3A8A216A4CE for ; Sun, 1 May 2005 12:39:08 +0000 (GMT) Received: from ylpvm12.prodigy.net (ylpvm12-ext.prodigy.net [207.115.57.43]) by mx1.FreeBSD.org (Postfix) with ESMTP id AF39A43D49 for ; Sun, 1 May 2005 12:39:07 +0000 (GMT) (envelope-from antennex@swbell.net) Received: from pimout6-ext.prodigy.net (pimout6-ext.prodigy.net [207.115.63.78])j41Cd52j014494 for ; Sun, 1 May 2005 08:39:06 -0400 X-ORBL: [65.68.247.73] Received: from SAGEAME (adsl-65-68-247-73.dsl.crchtx.swbell.net [65.68.247.73])j41Cd5XQ287954; Sun, 1 May 2005 08:39:06 -0400 Message-ID: <023201c54e4a$c40a8f60$0200000a@SAGEAME> From: "antenneX" To: "Alan Horn" , References: Date: Sun, 1 May 2005 07:39:06 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Subject: Re: question about mksnap_ffs and NFS interaction X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: antenneX List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 May 2005 12:39:08 -0000 ----- Original Message ----- From: "Alan Horn" To: Sent: Sunday, May 01, 2005 5:44 AM Subject: question about mksnap_ffs and NFS interaction > > Folks, > > I have some NFS exported filesystems (home directories) that I'm placing > under snapshots. > > Timing of making a snapshot on a 140GB filesystems running about 90% full > takes about 17 seconds. > > Given that these filesystems are fairly heavily used homedir filesystems, > what is the expected impact of those 17 seconds on NFS clients. > > My guess is that its enough to be seen but not enough to cause NFS > timeouts. So far I've been scheduling snapshots for the middle of the > night, but I'd like to start doing four per day. Does anyone have any data > on the likely impact ? > > Please reply direct to me as I'm not subbsed to the list. > > Cheers, > > Al > Glad to see a question on this subject and my reply is just more questions rather than an answer. I've just moved to 5.4RC3 & read most of the docs and this snap issue is new to me too. Howe are you scheduling? I noticed I never got a snapshot until I ran the command to do snaps on each FS. So, I scheduled one for "noon" as a cron job. Now I get a regular "snap" plus the "nooner", but they show a random time & both done about the same time. A mystery to me so far... sure like the new snap feature though.