From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stan Hoeppner Subject: Re: high throughput storage server? Date: Mon, 21 Mar 2011 12:07:45 -0500 Message-ID: <4D8785E1.6060700@hardwarefreak.com> References: <4D7E0994.3020303@hardwarefreak.com> <20110314124733.GA31377@infradead.org> <4D835B2A.1000805@hardwarefreak.com> <20110318140509.GA26226@infradead.org> <4D837DAF.6060107@hardwarefreak.com> <20110319090101.1786cc2a@notabene.brown> <4D8559A2.6080209@hardwarefreak.com> <20110320144147.29141f04@notabene.brown> <4D868C36.5050304@hardwarefreak.com> <20110321024452.GA23100@www2.open-std.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Roberto Spadim Cc: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= , Mdadm , NeilBrown , Christoph Hellwig , Drew List-Id: linux-raid.ids Roberto Spadim put forth on 3/20/2011 10:14 PM: > with hardware raid we don't think about this problem, but with > software we should consider since we run others app with software raid > running too Which is precisely why I asked Neil about this. If you recall Neil stated that CPU burn shouldn't be an issue when using mdraid linear over 16 mdraid 10 arrays in the proposed system. As long as the kernel somewhat evenly distributes IO steams amongst multiple cores I'm inclined to agree with Neil. Note that the application in this case, the NFS server, is threaded kernel code, and thus very fast and scalable across all CPUs. By design, all of the performance critical code in this system runs in kernel space. -- Stan