From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: how to debug slow rbd block device Date: Wed, 23 May 2012 10:20:43 +0200 Message-ID: <4FBC9DDB.5090507@profihost.ag> References: <4FBB8A5B.9010500@profihost.ag> <4FBBEBC8.1000205@profihost.ag> <1C70F3FB753C4AEC97247E04FAE3C733@inktank.com> <4FBBF74C.9020608@profihost.ag> <45F1742481D84E7A90951816DB23609F@inktank.com> <4FBBFE7B.4060406@profihost.ag> <65E9589544C4489F93761035433ADC01@inktank.com> <4FBC811F.5060004@profihost.ag> <4FBC83F3.7070400@inktank.com> <4FBC8B41.1020300@profihost.ag> <4FBC8F8F.6060004@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.profihost.ag ([85.158.179.208]:58381 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756548Ab2EWIUg (ORCPT ); Wed, 23 May 2012 04:20:36 -0400 In-Reply-To: <4FBC8F8F.6060004@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Josh Durgin Cc: Greg Farnum , ceph-devel@vger.kernel.org Am 23.05.2012 09:19, schrieb Josh Durgin: > On 05/23/2012 12:01 AM, Stefan Priebe - Profihost AG wrote: >> Am 23.05.2012 08:30, schrieb Josh Durgin: >>> On 05/22/2012 11:18 PM, Stefan Priebe - Profihost AG wrote: >>>> Hi, >>>> >>>>>> So try enabling RBD writeback caching =E2=80=94 see http://marc.= info >>>>>> /?l=3Dceph-devel&m=3D133758599712768&w=3D2 >>>>>> will test tomorrow. Thanks. >>>> Can we path this to the qemu-drive option? >>> >>> Yup, see >>> http://article.gmane.org/gmane.comp.file-systems.ceph.devel/6400 >> I'm sorry, i still don't get it where to pass rbd_cache_max_dirty, .= =2E. >> can i add it just to the ceph.conf? Even with qemu 1.0? >=20 > You can use any of the rbd-specific options (like rbd_cache_max_dirty= ) > with qemu >=3D 0.15. >=20 > You can set them in a global ceph.conf file, or specify them on the q= emu > command line like: >=20 > qemu -m 512 -drive > file=3Drbd:pool/image:rbd_cache_max_dirty=3D0:rbd_cache=3Dtrue,format= =3Draw,if=3Dvirtio So this is enough for testing on kvm host? /etc/ceph/ceph.conf [global] auth supported =3D cephx keyring =3D /etc/ceph/$name.keyring rbd_cache =3D true rbd_cache_size =3D 32M rbd_cache_max_age =3D 2.0 =2E.. 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