From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2C562C433FE for ; Wed, 16 Nov 2022 14:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668609624; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=tk9NpDN5KKz1QHgTL6hG6S8/u5mEdJnVjH7tjIVBrDs=; b=G8toBtX3WsbZfDGKSyDb4S/CizvNA7tcJvtv+WCpg2wBQavBT9gY8ulVDXG5cdWTyMUvQd jYyDs8jXpe1B7N1hV9Uok1EnPdb6d4LoJO0WoAitnZx/EE84rmDlDjM7SL9Qbivq9hKW3C Q9Q19BZPeAgBAAaQZfrk2c2LOmoFMbA= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-326-OevlWtgiP3aG1sddpt3GUw-1; Wed, 16 Nov 2022 09:40:20 -0500 X-MC-Unique: OevlWtgiP3aG1sddpt3GUw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4C7BF1C08979; Wed, 16 Nov 2022 14:40:18 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id B1EF3492B04; Wed, 16 Nov 2022 14:40:14 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id B3CAC19465A4; Wed, 16 Nov 2022 14:40:12 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id C517819465A2 for ; Wed, 16 Nov 2022 14:38:39 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id A548E17582; Wed, 16 Nov 2022 14:38:39 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast03.extmail.prod.ext.rdu2.redhat.com [10.11.55.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9D728FD48 for ; Wed, 16 Nov 2022 14:38:39 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 82728811E81 for ; Wed, 16 Nov 2022 14:38:39 +0000 (UTC) Received: from plutone.assyoma.it (host195-56-237-212.serverdedicati.aruba.it [212.237.56.195]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-38--csRrdspMg-XYPzm45QBiw-1; Wed, 16 Nov 2022 09:38:36 -0500 X-MC-Unique: -csRrdspMg-XYPzm45QBiw-1 Received: from webmail.assyoma.it (localhost [IPv6:::1]) by plutone.assyoma.it (Postfix) with ESMTPA id A04971451AF1; Wed, 16 Nov 2022 15:38:34 +0100 (CET) MIME-Version: 1.0 Date: Wed, 16 Nov 2022 15:38:34 +0100 From: Gionatan Danti To: Zdenek Kabelac In-Reply-To: <8865e8e7-fede-d904-8970-771afae19504@gmail.com> References: <8404c979411230748aa52deacca89cd8@assyoma.it> <0c1d5e76-085c-cb46-c477-3bcd70a8acb2@gmail.com> <8865e8e7-fede-d904-8970-771afae19504@gmail.com> User-Agent: Roundcube Webmail/1.4.13 Message-ID: <99746334610331ae0f7cca166649fdd0@assyoma.it> X-Sender: g.danti@assyoma.it X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Subject: Re: [linux-lvm] lvm-vdo, snapshots and cache X-BeenThere: linux-lvm@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: LVM general discussion and development Cc: LVM general discussion and development Errors-To: linux-lvm-bounces@redhat.com Sender: "linux-lvm" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Il 2022-11-16 11:50 Zdenek Kabelac ha scritto: > Well - as said - vg on vg is basically equivalent of the original LV > on top of VDO manager. Hi Zdenek, it seems clunkier to manage two nested VG/LV if you ask me. > But still these fast snapshot do not solve you a problem of double > out-of-space fault. Yeah, but available space requires constant monitor even when dealing with lvmthin. > It's good for experimenting - but I'd not suggest to use this setup. In RHEL7 it was specifically supported - see here[1]: "As a general rule, you should place certain storage layers under VDO and others on top of VDO: Under VDO: DM-Multipath, DM-Crypt, and software RAID (LVM or mdraid). On top of VDO: LVM cache, LVM snapshots, and LVM Thin Provisioning" For a practical example: in the past I experimented with a storage stack composed of raid -> vdo -> lvmthin -> xfs serving qemu/kvm virtual disk files. The lvmthin layer enabled rolling snapshots, and was a key feature of the test setup. Now the only method to replicate that is to have two nested LVM instances, one running vdo and one lvmthin - right? Regards. [1] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/vdo-qs-requirements -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti@assyoma.it - info@assyoma.it GPG public key ID: FF5F32A8 _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/