From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Nelson Subject: Re: flashcache Date: Thu, 17 Jan 2013 07:34:40 -0600 Message-ID: <50F7FDF0.6010809@inktank.com> References: <50F72150.7080002@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ie0-f174.google.com ([209.85.223.174]:37725 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751058Ab3AQNeo (ORCPT ); Thu, 17 Jan 2013 08:34:44 -0500 Received: by mail-ie0-f174.google.com with SMTP id c11so4736401ieb.33 for ; Thu, 17 Jan 2013 05:34:44 -0800 (PST) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Stefan Priebe - Profihost AG Cc: Sage Weil , Gandalf Corvotempesta , "ceph-devel@vger.kernel.org" On 01/16/2013 11:47 PM, Stefan Priebe - Profihost AG wrote: > Hi Mark, > > Am 16.01.2013 um 22:53 schrieb Mark >> With only 2 SSDs for 12 spinning disks, you'll need to make sure the SSDs are really fast. I use Intel 520s for testing which are great, but I wouldn't use them in production. > > Why not? I use them for a ssd only ceph cluster. > > Stefan It's pretty tough to get an apples-to-apples comparison of endurance when looking at the Intel 520 vs something like the DC S3700. If I were actually building out a production deployment I'd probably stick with the DC S3700 (especially if sticking journals, flashcache, and xfs journals for 6 osds on 1 drive!). There's probably a reasonable endurance per cost argument for a severely under-subscribed 520 (or other similar drive) as well. It'd be an interesting study to look at how long it takes a small enterpise drives to die vs a larger under-subscribed consumer drive. -- Mark Nelson Performance Engineer Inktank