From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Subject: Re: BlueStore and maximum number of objects per PG Date: Wed, 22 Feb 2017 17:34:22 +0300 Message-ID: <1487774062.1919.1.camel@gmail.com> References: <1002796178.10638.1487707472256@ox.pcextreme.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mail-lf0-f49.google.com ([209.85.215.49]:36409 "EHLO mail-lf0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932596AbdBVOe0 (ORCPT ); Wed, 22 Feb 2017 09:34:26 -0500 Received: by mail-lf0-f49.google.com with SMTP id b80so2283336lfe.3 for ; Wed, 22 Feb 2017 06:34:25 -0800 (PST) In-Reply-To: <1002796178.10638.1487707472256@ox.pcextreme.nl> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Wido den Hollander , ceph-devel On Tue, 2017-02-21 at 21:04 +0100, Wido den Hollander wrote: > Hi, > > I'm about to start a test where I'll be putting a lot of objects into BlueStore and > see how it holds. > > The reasoning behind is that I have a customer which has 165M objects in it's cluster > which results in some PGs having 900k objects. > > For FileStore with XFS this is quite heavy. A simple scrub takes ages. > > The problem is that we can't simply increase the number of PGs since that will > overload the OSDs as well. Also the problem stands if have a huge amount _small_ objects: capacity of hardware is enough (20% used) but PG quantity isn't. > > On the other hand we could add hardware, but that also takes time. > > So just for the sake of testing I'm looking at trying to replicate this situation > using BlueStore from master. > > Is there anything I should take into account? I'll probably be just creating a lot > (millions) of 100 byte objects in the cluster with just a few PGs. > > Wido > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html