From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinz Mauelshagen Subject: Re: dm-cache module Date: Wed, 28 Apr 2010 10:21:47 +0200 Message-ID: <1272442907.2031.79.camel@o> References: <4BA5623F.8040502@daevel.fr> <20100321033704.GA6448@redhat.com> <15606e421003202156n21de56a6n868f84bf737cce51@mail.gmail.com> <1269270327.21395.42.camel@o> <4BD7906E.6010602@daevel.fr> Reply-To: heinzm@redhat.com, device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BD7906E.6010602@daevel.fr> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com List-Id: dm-devel.ids On Wed, 2010-04-28 at 03:33 +0200, Olivier B. wrote: > 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 ? Yes, it looks like it. I'll have a closer look how it differs form mine. Heinz > > -- > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel