From mboxrd@z Thu Jan 1 00:00:00 1970 From: maurice Subject: Re: SSD - TRIM command Date: Tue, 08 Feb 2011 14:18:28 -0700 Message-ID: <4D51B324.5060901@gmail.com> References: <4D517F4F.4060003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: 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 2/8/2011 1:50 PM, Roberto Spadim wrote: > =] now the right answer :) > question: maybe in future... could we make trim compatible with md? > I hope that future is "real soon now" MLC SSD is now starting to appear in the "Enterprise space. Companies like Pliant have released products for that. Typical SAN RAID controllers have specific performance limits which can be saturated with a not very large number of SSDs. To get higher IOs we need a more powerful RAID engine A typical 48 core, 128GB RAM box using AMD CPUs and 4 SAS HBAs to disk JBD cases can be a ridiculously power RAID engine for a reasonable cost ( at least reasonable compered to NetApp, EMC, Hitachi SANs, etc) with a large number of devices. BUT: To use SSDs in the design we need mdadm to be more SSD friendly. -- Cheers, Maurice Hilarius eMail: /mhilarius@gmail.com/