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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 383DCC2B9F4 for ; Mon, 28 Jun 2021 04:23:27 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B8D8061C34 for ; Mon, 28 Jun 2021 04:23:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8D8061C34 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gathman.org Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-lvm-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-513-LkdavMaTMYO1Jv5BcGyTLQ-1; Mon, 28 Jun 2021 00:23:23 -0400 X-MC-Unique: LkdavMaTMYO1Jv5BcGyTLQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B5E27107AD81; Mon, 28 Jun 2021 04:23:15 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 031C05C1C5; Mon, 28 Jun 2021 04:23:13 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id BFA2D4EA2A; Mon, 28 Jun 2021 04:22:59 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 15S4MttJ014759 for ; Mon, 28 Jun 2021 00:22:55 -0400 Received: by smtp.corp.redhat.com (Postfix) id 4B5A39D54; Mon, 28 Jun 2021 04:22:55 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast01.extmail.prod.ext.rdu2.redhat.com [10.11.55.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4697E51DD for ; Mon, 28 Jun 2021 04:22:51 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (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 B4A1989B841 for ; Mon, 28 Jun 2021 04:22:51 +0000 (UTC) Received: from mail.gathman.org (mail.gathman.org [70.184.247.44]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-408-DQUJ0A2iPICGI-N9pH1Aww-1; Mon, 28 Jun 2021 00:22:47 -0400 X-MC-Unique: DQUJ0A2iPICGI-N9pH1Aww-1 Received: from wiki.gathman.org (mail.gathman.org [IPv6:2001:470:8:809::1010]) (authenticated bits=0) by mail.gathman.org (8.14.7/8.14.7) with ESMTP id 15S3SK3Y024992 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sun, 27 Jun 2021 23:28:23 -0400 Date: Sun, 27 Jun 2021 23:28:20 -0400 (EDT) From: Stuart D Gathman To: LVM general discussion and development In-Reply-To: Message-ID: References: <2d5ff29e-2836-0407-ce76-271255487baa@redhat.com> MIME-Version: 1.0 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 2.79 on 10.11.54.5 X-loop: linux-lvm@redhat.com Cc: Zhong Lidong , David Teigland , Zdenek Kabelac Subject: Re: [linux-lvm] Does LVM have any plan/schedule to support btrfs in fsadm X-BeenThere: linux-lvm@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-lvm-bounces@redhat.com Errors-To: linux-lvm-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-lvm-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" On Mon, 28 Jun 2021, heming.zhao@suse.com wrote: > In my opinion, the using style of btrfs by many users are same as ext4/xfs. Yes. I like the checksums in metadata feature for enhanced integrity checking. It seems too complicated to have anytime soon - but when a filesystem detects corruption, and is on an LVM (or md) RAID1 layer, an ioctl to read alternate mirror branches to see which (if any) has the correct data would allow recovery. Btrfs does this if it is doing the mirroring, but then you lose all the other features from LVM or md raid10, including running other filesystems and efficient virtual disks for virtual machines. We eventually got DISCARD operations to pass to lower layers. Dealing with mirror branches should really be a thing too. _______________________________________________ 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/