From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Olivier B." Subject: Re: dm-cache module Date: Wed, 28 Apr 2010 03:33:34 +0200 Message-ID: <4BD7906E.6010602@daevel.fr> References: <4BA5623F.8040502@daevel.fr> <20100321033704.GA6448@redhat.com> <15606e421003202156n21de56a6n868f84bf737cce51@mail.gmail.com> <1269270327.21395.42.camel@o> Reply-To: dm-devel@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1269270327.21395.42.camel@o> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: heinzm@redhat.com Cc: Ming Zhao , dm-devel@redhat.com, Mike Snitzer List-Id: dm-devel.ids On 22/03/2010 16:05, Heinz Mauelshagen wrote: > On Sun, 2010-03-21 at 00:56 -0400, Ming Zhao wrote: > >> Hi Mike, >> >> Thank you very much for your advice! >> >> I can revise dm-cache code and resubmit it as you suggested. I would >> also love to know Heinz's progress on his implementation and work with >> him if there anything I could contribute. >> > Hi all, > > this is a list of the functions of my dm-hstore > device-mapper target implementation: > > o caches reads and writes keeping persistent state metadata. > o writes back in order to enhance streaming performance > on fragmented access pattern. > o can run on top of readonly original device > o if so, writes back any dirty areas when set readwrite > (useful for tests) > o readonly<-> readwrite access changes supported via message interface > o initializes metadata for extents in cache in the background > in order to fasten cache construction > o supports cache resizing via message interface or constructor > o keeps metadata persistent by default > o stores CRCs with metadata for integrity checks > o stores versions with metadata to support future metadata migration > > Test features only: > o transient cache > o cache write through > > > Provides very good performance on SSD cache backing stores. > > Has been shelved for a while because of other priorities so I need to > rebase it to the actual kernel. > > Regards, > Heinz > > Hi, Facebook have just released "FlashCache" : http://github.com/facebook/flashcache in the documentation we can read : Flashcache is built using the Linux Device Mapper (DM), part of the Linux Storage Stack infrastructure that facilitates building SW-RAID and other components. So it's an other implementation of the same concept, no ?