From owner-freebsd-questions@FreeBSD.ORG Thu Apr 26 16:53:34 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id AD29816A404 for ; Thu, 26 Apr 2007 16:53:34 +0000 (UTC) (envelope-from speedtoys.racing@gmail.com) Received: from wr-out-0506.google.com (wr-out-0506.google.com [64.233.184.224]) by mx1.freebsd.org (Postfix) with ESMTP id 5613E13C457 for ; Thu, 26 Apr 2007 16:53:34 +0000 (UTC) (envelope-from speedtoys.racing@gmail.com) Received: by wr-out-0506.google.com with SMTP id 70so627163wra for ; Thu, 26 Apr 2007 09:53:33 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=MNR89+Hrlq2kRu/oxv50MSK0kGmoC2ZY0IxOQ7W6XLikEMgpXW0oe2JuF/A2b8ZSm6iZGQRgj329mnskbBybTJxGsm9k/s/vuNazV0ujhCkiB/8cIclozNtNdaMod5fJKvzvmQ2SeXsOxb1IE+0lesLfSBOskPIx/4bwythPrLM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=NgdPHm7p8XqtnHxKkelpy26YPvk3TMVZoDZq8gVlS8tbqeMG8uQ0WHv9+NgbSLqyE7RKfi4Xyx+LMjG8AXigGSwXhx6kTMzn/iET3/67WZmo2LuA00jwDwcGNXVI2Sgiy0CXfXWnTrKJkciXx+yPG/0xnRDSe75QpiYYcZuumRY= Received: by 10.78.160.2 with SMTP id i2mr561068hue.1177606412557; Thu, 26 Apr 2007 09:53:32 -0700 (PDT) Received: by 10.78.21.13 with HTTP; Thu, 26 Apr 2007 09:53:32 -0700 (PDT) Message-ID: Date: Thu, 26 Apr 2007 09:53:32 -0700 From: "Jeff Mohler" To: "GARRISON, TRAVIS J." In-Reply-To: <06D1B6D4926222458F803D0D3EDCCB7E01D0A790@EXM1.otc.edu> MIME-Version: 1.0 References: <200704260635.l3Q6ZZhL090019@banyan.cs.ait.ac.th> <06D1B6D4926222458F803D0D3EDCCB7E01D0A790@EXM1.otc.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-questions@freebsd.org Subject: Re: Single Instance Service X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Apr 2007 16:53:34 -0000 It can if your storage appliance supports ASIS. Some even operate at the block level, not just the file level. On 4/26/07, GARRISON, TRAVIS J. wrote: > > > -----Original Message----- > > From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd- > > questions@freebsd.org] On Behalf Of Olivier Nicole > > Sent: Thursday, April 26, 2007 1:36 AM > > To: m.seaman@infracaninophile.co.uk > > Cc: GARRISON, TRAVIS J.; freebsd-questions@freebsd.org > > Subject: Re: Single Instance Service > > > > > Sure it is. You will need to write a small shell script to scan > > > your disk volume and calculate the checksum of each file. When > > > ever it finds a duplicated checksum, then it copies the file into > > > the central store and replaces the on-disk copies with symbolic > > > links. That's fairly trivial to write. > > > > Beside, what should be the behaviour when one wishes to modify his own > > copy of a document? How does Single Instance acts in that case? > > > > If you establish a link, there is only one version of the file, once > > and forever (unless you go and unlink it manually), so when one > > modifies the file, modification applies for everyone. > > > > Olivier > [GARRISON, TRAVIS J.] > > I know with Windows Storage Server, if a user modifies the file, it will > then create the user their own copy of the file. This happens > automatically. Exchange Server is another example of this type of > storage. When someone sends an attachment to several people, the server > saved one copy of the file. I am currently managing 7TB worth of data > with roughly 1 to 2TB of duplicate files. This gets fairly expensive > with a fiber channel san backend. I know it can be done in the windows > world automatically, just wondered if it could be done automatically in > the Unix world also. > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscribe@freebsd.org" >