From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wido den Hollander Subject: RBD stall when creating and listing images Date: Sat, 21 Apr 2012 13:26:28 +0200 Message-ID: <4F929964.8000506@widodh.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp01.mail.pcextreme.nl ([109.72.87.137]:44780 "EHLO smtp01.mail.pcextreme.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752605Ab2DUL0b (ORCPT ); Sat, 21 Apr 2012 07:26:31 -0400 Received: from [IPv6:2a00:f10:11c:ab:52e5:49ff:fec2:c976] (unknown [IPv6:2a00:f10:11c:ab:52e5:49ff:fec2:c976]) by smtp01.mail.pcextreme.nl (Postfix) with ESMTPA id 3A3EF7619A for ; Sat, 21 Apr 2012 13:26:29 +0200 (CEST) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" Hi, I was just playing with my libvirt driver and I noticed a stall. On one host I had running: for i in {0..8192}; do rbd create --size 64 image-$i; echo "created image-$i"; done And on the other host I was running a pool-refresh in libvirt. As I was tailing the libvirt log I noticed that it had stalled, so I checked my other terminal and saw that the creation of new images had also stalled. This situation persisted for about ~20 seconds and then everything started to continue. At the moment of the stall libvirt was calling rbd_list and was not doing any rbd_stat yet. I'm trying to reproduce it here, but I wonder if there is a logical explanation for this situation? I'm running 0.44 on my cluster and 0.45 on the client btw. Wido