From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Nelson Subject: Re: RBD fio Performance concerns Date: Thu, 22 Nov 2012 08:46:23 -0600 Message-ID: <50AE3ABF.7000709@inktank.com> References: <0a4a4396-60cd-4782-8743-b2bbba2d2488@mailpro> <50AE351F.9080505@profihost.ag> <50AE38C4.6000909@inktank.com> <50AE39C6.5010205@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-ie0-f174.google.com ([209.85.223.174]:60276 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752641Ab2KVSym (ORCPT ); Thu, 22 Nov 2012 13:54:42 -0500 Received: by mail-ie0-f174.google.com with SMTP id k11so2385054iea.19 for ; Thu, 22 Nov 2012 10:54:42 -0800 (PST) In-Reply-To: <50AE39C6.5010205@profihost.ag> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Stefan Priebe - Profihost AG Cc: Alexandre DERUMIER , ceph-devel , Mark Kampe , =?UTF-8?B?U8OpYmFzdGllbiBIYW4=?= I haven't played a whole lot with SSD only OSDs yet (other than noting=20 last summer that iop performance wasn't as high as I wanted it). Is a=20 second partition on the SSD for the journal not an option for you? Mark On 11/22/2012 08:42 AM, Stefan Priebe - Profihost AG wrote: > Am 22.11.2012 15:37, schrieb Mark Nelson: >> I don't think we recommend tmpfs at all for anything other than play= ing >> around. :) > > I discussed this with somebody frmo inktank. Had to search the > mailinglist. It might be OK if you're working with enough replicas an= d UPS. > > I see no other option while working with SSDs - the only Option would= be > to be able to deaktivate the journal at all. But ceph does not suppor= t > this. > > Stefan > >> On 11/22/2012 08:22 AM, Stefan Priebe - Profihost AG wrote: >>> Hi, >>> >>> can someone from inktank comment this? Might be using /dev/ram0 wit= h an >>> fs on it be better than tmpfs as we can use dio? >>> >>> Greets, >>> Stefan >>> >>>> ----- Mail original ----- >>>> >>>> De: "Stefan Priebe - Profihost AG" >>>> =C3=80: "S=C3=A9bastien Han" >>>> Cc: "Mark Nelson" , "Alexandre DERUMIER" >>>> , "ceph-devel" , >>>> "Mark Kampe" >>>> Envoy=C3=A9: Jeudi 22 Novembre 2012 14:29:03 >>>> Objet: Re: RBD fio Performance concerns >>>> >>>> Am 22.11.2012 14:22, schrieb S=C3=A9bastien Han: >>>>> And RAMDISK devices are too expensive. >>>>> >>>>> It would make sense in your infra, but yes they are really expens= ive. >>>> >>>> We need something like tmpfs - running in local memory but support= dio. >>>> >>>> Stefan >>>> >> >> --=20 Mark Nelson Performance Engineer Inktank -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html