From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: RBD fio Performance concerns Date: Thu, 22 Nov 2012 16:01:56 +0100 Message-ID: <50AE3E64.90702@profihost.ag> References: <0a4a4396-60cd-4782-8743-b2bbba2d2488@mailpro> <50AE351F.9080505@profihost.ag> <50AE38C4.6000909@inktank.com> <50AE39C6.5010205@profihost.ag> <50AE3ABF.7000709@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.profihost.ag ([85.158.179.208]:35288 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750898Ab2KVTCF (ORCPT ); Thu, 22 Nov 2012 14:02:05 -0500 In-Reply-To: <50AE3ABF.7000709@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Mark Nelson Cc: Alexandre DERUMIER , ceph-devel , Mark Kampe , =?UTF-8?B?U8OpYmFzdGllbiBIYW4=?= Am 22.11.2012 15:46, schrieb Mark Nelson: > I haven't played a whole lot with SSD only OSDs yet (other than notin= g > last summer that iop performance wasn't as high as I wanted it). Is = a > second partition on the SSD for the journal not an option for you? Haven't tested that. But does this makes sense? I mean data goes to Dis= k=20 journal - same disk then has to copy the Data from part A to part B. Why is this an advantage? Stefan > 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 pla= ying >>> around. :) >> >> I discussed this with somebody frmo inktank. Had to search the >> mailinglist. It might be OK if you're working with enough replicas a= nd >> UPS. >> >> I see no other option while working with SSDs - the only Option woul= d be >> to be able to deaktivate the journal at all. But ceph does not suppo= rt >> 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 wi= th 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 expen= sive. >>>>> >>>>> We need something like tmpfs - running in local memory but suppor= t >>>>> dio. >>>>> >>>>> Stefan >>>>> >>> >>> > > -- 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