From mboxrd@z Thu Jan 1 00:00:00 1970 From: sbp Subject: Re: dm-cache: clean cache resyncs to origin on every boot Date: Tue, 20 Oct 2015 20:00:25 +0200 Message-ID: <56268139.9010901@extio.de> References: <20151020143304.GA15948@rh-vpn> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20151020143304.GA15948@rh-vpn> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids On 10/20/2015 04:33 PM, Joe Thornber wrote: > On Tue, Oct 20, 2015 at 11:51:07AM +0500, Bogdan Vasiliev wrote: >> Hello, >> >> I have dm-cache configuraion with SSD in writeback mode. On every boot >> an entire cache resyncs to an origin device, even if it was clean >> before on shutdown. It takes time and full bandwidth of an origin >> device. >> >> Is there reason for this behavior or is it a bug? Why we do not trust >> a cache metadata? > If the cache is not taken down cleanly then dm-cache has to assume > every block is dirty. Make sure your shutdown scripts are removing > the cache device. Hi, I have the same problem, but also in writethrough mode. In principle the behavior is the same in writethrough and writeback modes: Cache is fully written back to disk every time the machine boots and sets the cache up. I've posted a similar report to this list beginning of this month, but got no answer. There is my exact startup and shutdown script included, also some additional information about the setup. https://www.redhat.com/archives/dm-devel/2015-October/msg00012.html > >> My configuration details, if necessary: >> storage-cache_cdata:0 41943040 linear >> storage-cache_cmeta: 0 1048576 linear >> storage-data: 0 1953513472 cache 8 989/131072 128 173945/327680 610488 >> 20046 574861 3817439 0 0 0 1 writeback 2 migration_threshold 2048 mq >> 10 random_threshold 4 sequential_threshold 512 >> discard_promote_adjustment 1 read_promote_adjustment 4 >> write_promote_adjustment 8 rw - >> storage-data_corig: 0 1953513472 linear >> >> >> - Bogdan >> >> -- >> dm-devel mailing list >> dm-devel@redhat.com >> https://www.redhat.com/mailman/listinfo/dm-devel > -- > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel