From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pawel Baldysiak Subject: Re: [PATCH 0/2] md: Add support for Multiple PPLs Date: Fri, 25 Aug 2017 22:02:07 +0200 Message-ID: References: <20170816151346.23382-1-pawel.baldysiak@intel.com> <20170817180331.baxoqhgbqi5q6fvx@kernel.org> <4e72946d-3bdc-8a69-0b44-591570aae3a2@intel.com> <20170821161426.of5z62r45unlh2en@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170821161426.of5z62r45unlh2en@kernel.org> Content-Language: en-US Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 08/21/2017 06:14 PM, Shaohua Li wrote> Can you elaborate more? > Storage presented to the host may have a RAID on the back-end. For NVMe SSDs, the 1.3 specification provided a field to advertise chunk boundaries: Identify Namespace NOIOB. We need to span the entire stripe to utilize the total available capacity, otherwise we'll repeatedly write to only a subset, increasing write amplification factor. The new PPL approach is designed to access the full capacity. Thanks Pawel