From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shin.romanrm.net (shin.romanrm.net [146.185.199.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B0B120B27 for ; Sat, 2 Mar 2024 15:56:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=146.185.199.61 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709395008; cv=none; b=vCfqUwbdn8YUzvIGv7qx1H9IT+tIn3v7ODw0yrD/S2vgb4jgiiRq/eaFj0DEP3N7TXpu0EPHZsOHHfZcaJ0M7nJdTVF5C1sgx4bW+F9wVaVqENYfY/PPBXTdT6mbwtuICtIAptXvTd1FYlhCNwDUGT4XfrEcZMB7GkGKsMFbS7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709395008; c=relaxed/simple; bh=JVpDii7bEPosS0TTW4nrSIoyqmk7U4WBzrDmhbZzHSs=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YKwXm4TjSETffySN3zRBnY64Bgq6gGbQoLMJHqnrKtqjdpRp/RmSqEHmYoZGLPExZDmBD/ZoIQXJJoYnlfMhVjn8/a1N9H/RmRYFjbEqALmqLDtzMgUhglK5VgN9IQ8A7ASvlLNg5O9t4cK0Qc5hpBYc3GZBxB+yE1ibKty4Dqk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=romanrm.net; spf=pass smtp.mailfrom=romanrm.net; arc=none smtp.client-ip=146.185.199.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=romanrm.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=romanrm.net Received: from nvm (unknown [IPv6:fd39::4a:3cff:fe57:d6b5]) by shin.romanrm.net (Postfix) with SMTP id 5727F3F8ED; Sat, 2 Mar 2024 15:47:32 +0000 (UTC) Date: Sat, 2 Mar 2024 20:47:26 +0500 From: Roman Mamedov To: Nigel Kukard Cc: linux-btrfs@vger.kernel.org Subject: Re: btrfs ontop of LVM ontop of MD RAID1 supported? Message-ID: <20240302204726.6d2dcd87@nvm> In-Reply-To: <1cfb237c-5583-44e9-8bad-d91f34e29972@LBSD.net> References: <1cfb237c-5583-44e9-8bad-d91f34e29972@LBSD.net> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sat, 2 Mar 2024 15:01:43 +0000 Nigel Kukard wrote: > I'm wondering if btrfs ontop of LVM ontop of MD RAID1 is supported?=C2=A0= =20 Should be absolutely supported. > I've managed to reproduce with 100% accuracy severe data corruption=20 > using this configuration on 6.6.19. >=20 > 2 x 1.92T NVMe's in MD RAID1 configuration > LVM volume created ontop of the MD RAID1 > btrfs filesystem on the LV >=20 > I then write about 100-200G of data. Create a snapshot. Read/write the=20 > file and get these messages... Has the MD RAID1 finished its initial sync after creation? Have you tried waiting until it finishes and only then do thewrites to see = if the corruption is still observed (of course that's in no way a "workaround", just to see what might cause the bug). Do you know any kernel versions or series where this corruption did not hap= pen? I assume you're not saying it appeared in 6.6.19 compared to 6.6.18. Can you try the 6.1 series? Or maybe also 6.8? I made a Btrfs on top of LVM on top of RAID1 myself now, but on consumer SS= Ds. Copying some files to it now, to check. Would be also helpful if you can fi= nd a precise sequence of commands which can trigger the bug, less vague than copy some files to it and see. --=20 With respect, Roman