From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com ([74.125.82.43]:38020 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751263AbcATLeG (ORCPT ); Wed, 20 Jan 2016 06:34:06 -0500 Subject: Re: Kernel 4.4.0 KVM guest on Btrfs locks up on snapshotting To: Roman Mamedov , bo.li.liu@oracle.com References: <20160120030223.22cc3ae0@natsu> <20160120001944.GA9884@localhost.localdomain> <20160120100852.470479a6@natsu> Cc: linux-btrfs@vger.kernel.org, kvm@vger.kernel.org From: Paolo Bonzini Message-ID: <569F70AA.2030006@redhat.com> Date: Wed, 20 Jan 2016 12:34:02 +0100 MIME-Version: 1.0 In-Reply-To: <20160120100852.470479a6@natsu> Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 20/01/2016 06:08, Roman Mamedov wrote: > I don't get any ENOSPC errors on the host, also it doesn't seem to > be a slowdown caused by disk I/O searching for free space, just a > complete lock-up: I monitor the guest with 'ping', and when it > happens, the ping responses stop immediately and do not return, > also there is no reaction to any keypress in the KVM VNC window. Can you go to the QEMU monitor (Ctrl-Alt-F2 typically, or just add "-monitor stdio" to the QEMU command line) and type "info status"? Paolo