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 16:00:27 +0100 Message-ID: <50AE3E0B.8080905@profihost.ag> References: <8789b7e3-daa1-4f81-88a2-59329a5c382a@mailpro> 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]:41173 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755511Ab2KVTAf (ORCPT ); Thu, 22 Nov 2012 14:00:35 -0500 In-Reply-To: <8789b7e3-daa1-4f81-88a2-59329a5c382a@mailpro> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alexandre DERUMIER Cc: ceph-devel , Mark Kampe , =?UTF-8?B?U8OpYmFzdGllbiBIYW4=?= , Mark Nelson Am 22.11.2012 15:52, schrieb Alexandre DERUMIER: >>> I discussed this with somebody frmo inktank. Had to search the >>> mailinglist. It might be OK if you're working with enough replicas = and UPS. >>> >>> I see no other option while working with SSDs - the only Option wou= ld be >>> to be able to deaktivate the journal at all. But ceph does not supp= ort this. > > Do you have a big difference with putting 1 journal by osd on each ss= d drive ? Not tested. > another alternative can be (but indeed costly): > > - stec zeus ram ssd drive, around 2000$ for 8G (I have benched it aro= und 100000 iops ;) > - ddrdrive (http://www.ddrdrive.com/) (around 200000iops, don't know = the price) > - fusionio card (iodrive2, 360GB, around 3000=E2=82=AC , but they are= 160GB model, maybe half the price) All too expensive. > - maybe ocz talos, around 600=E2=82=AC for OCZ Talos 2 R 200 Go (don'= t have benched them, but spec say around 35000iops random) Not usable as each OSD can do 35.000 random IOP/s in my case and have 8= =20 of them in each node... Stefan > ----- Mail original ----- > > De: "Stefan Priebe - Profihost AG" > =C3=80: "Mark Nelson" > Cc: "Alexandre DERUMIER" , "ceph-devel" , "Mark Kampe" , "S=C3=A9ba= stien Han" > Envoy=C3=A9: Jeudi 22 Novembre 2012 15:42:14 > Objet: Re: RBD fio Performance concerns > > 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 >>>> >> >> -- 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