From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: mirrored device with thousand of mappingtableentries Date: Mon, 28 Feb 2011 10:01:56 -0500 Message-ID: References: <20110228114801.GZ3626@agk-dp.fab.redhat.com> <20110228121149.GA3626@agk-dp.fab.redhat.com> <20110228131028.GB3626@agk-dp.fab.redhat.com> <4D6BA566.1050305@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D6BA566.1050305@redhat.com> (Zdenek Kabelac's message of "Mon, 28 Feb 2011 14:38:46 +0100") 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 >>>>> "Zdenek" == Zdenek Kabelac writes: Zdenek> If you really need that many devices - be also sure you have Zdenek> disabled this kernel config option: Zdenek> CONFIG_BLK_DEV_INTEGRITY Zdenek> For some reason it consumes massive amount of memory. Other Zdenek> than that - you should count with 64KB per device usually. Care to qualify that? Unless your HBA indicates that it supports data integrity the only penalty should be that each bio grows a pointer. -- Martin K. Petersen Oracle Linux Engineering