From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zdenek Kabelac Subject: Re: Reducing size of thin spare metadata, thin metadata Date: Mon, 06 Oct 2014 09:39:30 +0200 Message-ID: <54324732.5080107@redhat.com> References: Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: patrik@dsl.sk Cc: device-mapper development List-Id: dm-devel.ids Dne 6.10.2014 v 09:28 Patrik Horn=EDk napsal(a): > Hi, > > is it possible to (safely) reduce size of thin metadata and / or thin > spare metadata? What size of spare metadata is needed? Can it be > smaller than size of pool metadata? > You could remove pool spare volume anytime - lvremove. (it's only used for automated lvconvert --repair) Repair needs free space in VG - if there is no free space - well tool can't= be = used. You could also reduce size of thin pool metadata in case it's too big, just = not online. With offline thinpool with these manual steps (will be later automated with tool as well): -- make a temporary LV of any size. swap this temp LV with pool metadata # lvconvert --thinpool vg/mypool --poolmetadata mytemplv Create your volume for metadata with new reduced size (unsure which size is your target - but some calcs based on estimated usage = are necessary) Activate mytemplv which has now real metadata from thinpool. # thin_repair -i /dev/vg/mytemplv -o /dev/vg/mynewsizemeta # thin_check /dev/vg/mynewsizemeta If all is green - swap new meta into your thinpool # lvconvert --thinpool vg/mypool --poolmetadata mynewsizemeta If all works great you are done :) In all other cases you have your backup at hand :) Yeah - you still have old metadata in mytemplv - this volume you may remove later if all works well - otherwise you may try to swap this volume back. Zdenek