From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx08.extmail.prod.ext.phx2.redhat.com [10.5.110.32]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uA8FFgC9007683 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 8 Nov 2016 10:15:43 -0500 Received: from strike.wu.ac.at (strike.wu-wien.ac.at [137.208.89.120]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B94DBC057FAD for ; Tue, 8 Nov 2016 15:15:40 +0000 (UTC) Message-ID: <5821EC1A.306@strike.wu.ac.at> Date: Tue, 08 Nov 2016 16:15:38 +0100 From: "Alexander 'Leo' Bergolth" MIME-Version: 1.0 References: <582049AF.7010905@strike.wu.ac.at> <6c916712-d43b-d456-9a4b-f8c801201639@redhat.com> <5820A497.80501@strike.wu.ac.at> <3c20480f-45e2-5864-cebc-ddc43b563944@redhat.com> In-Reply-To: <3c20480f-45e2-5864-cebc-ddc43b563944@redhat.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] very slow sequential writes on lvm raid1 (bitmap?) Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@redhat.com On 11/08/2016 10:26 AM, Zdenek Kabelac wrote: > Dne 7.11.2016 v 16:58 Alexander 'Leo' Bergolth napsal(a): >> On 11/07/2016 11:22 AM, Zdenek Kabelac wrote: >> Is there a way to change the regionsize for an existing LV? > > I'm afraid there is not yet support for runtime 'regionsize' change > other then rebuilding array. Unfortunately even rebuilding (converting to linear and back to raid1) doesn't work. lvconvert seems to ignore the --regionsize option and use defaults: lvconvert -m 0 /dev/vg_sys/lv_test lvconvert --type raid1 -m 1 --regionsize 128M /dev/vg_sys/lv_test [10881847.012504] mdX: bitmap initialized from disk: read 1 pages, set 4096 of 4096 bits ... which translates to a regionsize of 512k for a 2G volume. :-( Cheers, --leo -- e-mail ::: Leo.Bergolth (at) wu.ac.at fax ::: +43-1-31336-906050 location ::: IT-Services | Vienna University of Economics | Austria