From mboxrd@z Thu Jan 1 00:00:00 1970 From: Constantinos Venetsanopoulos Subject: Re: Experiences with Ceph at the June'14 issue of USENIX ;login: Date: Tue, 03 Jun 2014 12:12:12 +0300 Message-ID: <538D916C.4020801@grnet.gr> References: <20140602183219.GD17479@philipgian-mac> <20140602214040.GG4356@orbis-terrarum.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from averel.grnet-hq.admin.grnet.gr ([195.251.29.3]:25327 "EHLO averel.grnet-hq.admin.grnet.gr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbaFCJ01 (ORCPT ); Tue, 3 Jun 2014 05:26:27 -0400 In-Reply-To: <20140602214040.GG4356@orbis-terrarum.net> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "Robin H. Johnson" , ceph-devel@vger.kernel.org Hello Robin, On 6/3/14, 24:40 AM, Robin H. Johnson wrote: > On Mon, Jun 02, 2014 at 09:32:19PM +0300, Filippos Giannakos wrote: >> As you may already know, we have been using Ceph for quite some time now to back >> the ~okeanos [1] public cloud service, which is powered by Synnefo [2]. > (Background info for other readers: Synnefo is a cloud layer on top of > Ganeti). > >> In the article we describe our storage needs, how we use Ceph and how it has >> worked so far. I hope you enjoy reading it. > Are you just using the existing kernel RBD mapping for Ganeti running > KVM, or did you implement the pieces for Ganeti to use the QEMU > userspace RBD driver? Non of the above. From the Ceph project we are just using RADOS, which we access via an Archipelago [1] backend driver that uses librados from userspace. We integrate Archipelago with Ganeti with the Archipelago ExtStorage provider. > I've got both Ceph & Ganeti clusters already, but am reluctant to marry > the two sets of functionality because the kernel RBD driver still seemed > to perform so much worse than the Qemu userspace RBD driver, and Ganeti > still hasn't implemented the userspace mapping pieces :-( > Ganeti supports accessing RADOS from userspace (via the qemu-rbd driver) since version 2.10. The current stable is 2.11. Not only that, but starting v2.13 (not released yet), you will be able to configure the access method per-disk, e.g. saying that the first disk of the instance will be kernel backed and the second userspace backed. So, I'd suggest you give it a try and see how it goes :) Thanks, Constantinos [1] https://www.synnefo.org/docs/archipelago/latest/