From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cory Coager Subject: Re: support for external persistent cache Date: Wed, 19 Jan 2011 11:29:41 -0500 Message-ID: <20110119162941.GA32537@erebus.underworld.local> References: <4D365551.7090207@gmail.com> <4D365BE2.9020300@gmail.com> <20110119155211.GA31671@erebus.underworld.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, Jan 19, 2011 at 02:16:08PM -0200, Roberto Spadim wrote: > ok, your hardware have: > cpu, memory, disk controller, disks > > and you computer have: > cpu, memory, disk controler (your hardware) > > if your computer cache don?t sync to your disk controller you will > lose information.... > > check that *memory, is the volatille memory and *disk controller is > the non volatille memory > if you tell me that you will never have a *memory, and you have always > a non volatille memory, no problem, you will never need a kernel > load... just a boot loader that read previous memory information and > start in that point... why don?t do this? non volatille memory is not > as fast as volatille memory > got the problem? Sorry, we're still not on the same page. I would use both a ramdisk and sata disk. The ramdisk would act as a persistent cache (with the battery) for the sata disks. Enabling write through would write to the cache first then sync to the sata disks. Understand what I'm getting at now?