From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.server123.net (Postfix) with ESMTPS for ; Wed, 10 Sep 2014 15:25:23 +0200 (CEST) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XRhtg-0007Bf-3N for dm-crypt@saout.de; Wed, 10 Sep 2014 15:25:20 +0200 Received: from c-24-14-20-249.hsd1.il.comcast.net ([24.14.20.249]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Sep 2014 15:25:20 +0200 Received: from rnicholsNOSPAM by c-24-14-20-249.hsd1.il.comcast.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Sep 2014 15:25:20 +0200 From: Robert Nichols Date: Wed, 10 Sep 2014 08:25:07 -0500 Message-ID: References: <20140909215203.GG26856@markov.biostat.ucsf.edu> <20140910033131.GD8520@markov.biostat.ucsf.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <20140910033131.GD8520@markov.biostat.ucsf.edu> Subject: Re: [dm-crypt] expanding encrypted volume/growing the volume List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de On 09/09/2014 10:31 PM, Ross Boylan wrote: > On Tue, Sep 09, 2014 at 08:59:03PM -0500, Robert Nichols wrote: >> Easy. Create a new LV in that VG and use "--extents 100%FREE" as >> its size. Fill that LV with whatever variety of random data you >> choose, then delete that LV and use the space to expand your active >> LV. > > Thanks; I wasn't aware of that syntax. > > But do the snapshots make that hazardous? If the maximum space I > specified for them is pre-allocated it should be fine, but I thought > the implementation grabbed blocks as needed. If that's the case, a > snapshot could fail while I have grabbed all the "free" space. > > I suppose worst case I could do 90%Free and be good enough. The snapshot LV can increase its size only if you created it as thinly provisioned, and even then it can grab extents only within the LV that you set up as a "thin pool" LV. The space within that thin pool LV is not "free" for the purposes of creating a new LV. Creating a new LV with "--extents 100%FREE" will not affect expansion of your snapshot LVs. -- Bob Nichols "NOSPAM" is really part of my email address. Do NOT delete it.