From patchwork Thu Mar 7 22:42:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Sakai X-Patchwork-Id: 13586325 X-Patchwork-Delegate: snitzer@redhat.com Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 174292E648 for ; Thu, 7 Mar 2024 22:42:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709851333; cv=none; b=YKxBa9Mlcv+31UXZbDD5awDRSwRJZ/Bj3kZg250+ULXB0j6UGZNx3yLe9WsfAx6Y9mtSkMt3diW5kXpt2fbtlq1b4qx3MdeAzQ83o4wStYVWdlmdkI3HlSKnoyTtbk0pGBt8033jybil5+ndM6c4cdtCgZ/v4YHAC9Ssc9vygnU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709851333; c=relaxed/simple; bh=ywBGcs/Xzhrdf03COrm1Tb09gutJjkaanTrdA4vqvoE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=M41P/rX5LoB/FkkoT4o3Ahe9YiME+d9KaHtDdY+Ji1P8CYSBZOfHIizwYRb47AVLD8OEccwuDOz1OGQA1+NVhzT4EnfPnfsO4h5X5bjBfLzy7VER6/wZi0d/NfCPWN5jb3qob1BI3llJYQBegU69BGsdgKklpUPCwQTGmROBDV8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=dKaKKgFE; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dKaKKgFE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709851331; h=from:from: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; bh=8Ou4XxDmFGVaYaQXCv4OSiXBL9RouOY+0ozhwhyXMbk=; b=dKaKKgFEl6HVzrYIIfiYd8XxfVR68FnmRA/Eicher09E3Yzm6g84gTLK+8BEgFiwtaEEVY MFIWzWZSxka/wP8zHIhy9+MvvGlV2E4fSg7l3VdyOUS8UZEUTGpxePdqxI5sokcon84cyc k3MfkrXzwlxQ+ur8ndq6304X/GzagWc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-139-f6FdmzFzOqWZE_O5ALNQiw-1; Thu, 07 Mar 2024 17:42:09 -0500 X-MC-Unique: f6FdmzFzOqWZE_O5ALNQiw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C37A380F7E7 for ; Thu, 7 Mar 2024 22:42:08 +0000 (UTC) Received: from vdo-builder-msakai.permabit.com (vdo-builder-msakai.permabit.lab.eng.bos.redhat.com [10.0.103.170]) by smtp.corp.redhat.com (Postfix) with ESMTP id BDCF710E4F; Thu, 7 Mar 2024 22:42:08 +0000 (UTC) Received: by vdo-builder-msakai.permabit.com (Postfix, from userid 1138) id AC152A2CEC; Thu, 7 Mar 2024 17:42:08 -0500 (EST) From: Matthew Sakai To: dm-devel@lists.linux.dev Cc: Matthew Sakai Subject: [PATCH] dm vdo doc: document metadata size Date: Thu, 7 Mar 2024 17:42:08 -0500 Message-ID: <9a8f119dfffac40f416dee63cbbb9778ed8e4a26.1709851277.git.msakai@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Signed-off-by: Matthew Sakai --- Documentation/admin-guide/device-mapper/vdo.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/admin-guide/device-mapper/vdo.rst b/Documentation/admin-guide/device-mapper/vdo.rst index a3572582ead8..7e1ecafdf91e 100644 --- a/Documentation/admin-guide/device-mapper/vdo.rst +++ b/Documentation/admin-guide/device-mapper/vdo.rst @@ -34,6 +34,17 @@ The repo also contains additional userspace tools which can be used to inspect a vdo target's on-disk metadata. Fortunately, these tools are rarely needed except by dm-vdo developers. +Metadata requirements +===================== + +Each vdo volume reserves 3GB of space for metadata, or more depending on +its configuration. It is helpful to check that the space saved by +deduplication and compression is not cancelled out by the metadata +requirements. An estimation of the space saved for a specific dataset can +be computed with the vdo estimator tool, which is available at: + +https://github.com/dm-vdo/vdoestimator/ + Target interface ================