From mboxrd@z Thu Jan 1 00:00:00 1970 References: <4081c11e-d2b0-ebfa-d1a0-92a4efc79e81@redhat.com> From: Zdenek Kabelac Message-ID: <643c43ad-0814-18a7-bb60-439adb4c6514@redhat.com> Date: Mon, 7 Sep 2020 19:50:35 +0200 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [linux-lvm] exposing snapshot block device 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="utf-8"; format="flowed" To: =?UTF-8?Q?Tomas_Dalebj=c3=b6rk?= Cc: LVM general discussion and development Dne 07. 09. 20 v 19:37 Tomas Dalebjörk napsal(a): > thanks > > ok > vgsplit/merge instead > and after that lvconvert-s > > yes, I am aware of the issues with corruption > but if the cow device has all data, than no corruption will happen, right? > > if COW has a copy of all blocks > than a lvconvert —merge, or mount of the snapshot volume will be without issues If the 'COW' has all the data - why do you need then snapshot ? Why not travel whole LV instead of snapshot ? Also - nowdays this old (so called 'thick') snapshot is really slow compared with thin-provisioning - might be good if you check what kind of features you can gain/loose if you would have switched to thin-pool (clearly whole thin-pool (both data & metadata) would need to travel between your VGs.) Regards Zdenek