From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46006) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YgCZE-0005FF-CV for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:32:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YgCZ3-00075g-JO for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:32:24 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:51912 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YgCZ3-00075F-6g for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:32:13 -0400 Message-ID: <55267F56.8050703@kamp.de> Date: Thu, 09 Apr 2015 15:32:06 +0200 From: Peter Lieven MIME-Version: 1.0 References: <5522D4BD.7080805@kamp.de> <5522D57B.3000203@redhat.com> <5522D85D.20907@kamp.de> <5522DA21.1010702@kamp.de> <20150407084303.GA2298@work-vm> <5523F38A.4090305@kamp.de> <20150407152957.GB2287@work-vm> <55242597.1000700@kamp.de> <20150407190112.GD2287@work-vm> <55267553.5000506@kamp.de> In-Reply-To: <55267553.5000506@kamp.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-block] Migration sometimes fails with IDE and Qemu 2.2.1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: Paolo Bonzini , John Snow , "qemu-devel@nongnu.org" , qemu-block@nongnu.org Am 09.04.2015 um 14:49 schrieb Peter Lieven: > Am 07.04.2015 um 21:01 schrieb Dr. David Alan Gilbert: >> * Peter Lieven (pl@kamp.de) wrote: >>> Am 07.04.2015 um 17:29 schrieb Dr. David Alan Gilbert: >>>> * Peter Lieven (pl@kamp.de) wrote: >>>>> Hi David, >>>>> >>>>> Am 07.04.2015 um 10:43 schrieb Dr. David Alan Gilbert: >>>>>>>>> Any particular workload or reproducer? >>>>>>>> Workload is almost zero. I try to figure out if there is a way to trigger it. >>>>>>>> >>>>>>>> Maybe playing a role: Machine type is -M pc1.2 and we set -kvmclock as >>>>>>>> CPU flag since kvmclock seemed to be quite buggy in 2.6.16... >>>>>>>> >>>>>>>> Exact cmdline is: >>>>>>>> /usr/bin/qemu-2.2.1 -enable-kvm -M pc-1.2 -nodefaults -netdev type=tap,id=guest2,script=no,downscript=no,ifname=tap2 -device e1000,netdev=guest2,mac=52:54:00:ff:00:65 -drive >>>>>>>> format=raw,file=iscsi://172.21.200.53/iqn.2001-05.com.equallogic:4-52aed6-88a7e99a4-d9e00040fdc509a3-XXX-hd0/0,if=ide,cache=writeback,aio=native -serial null -parallel null -m 1024 -smp 2,sockets=1,cores=2,threads=1 -monitor >>>>>>>> tcp:0:4003,server,nowait -vnc :3 -qmp tcp:0:3003,server,nowait -name 'XXX' -boot order=c,once=dc,menu=off -drive index=2,media=cdrom,if=ide,cache=unsafe,aio=native,readonly=on -k de -incoming tcp:0:5003 -pidfile /var/run/qemu/vm-146.pid >>>>>>>> -mem-path /hugepages -mem-prealloc -rtc base=utc -usb -usbdevice tablet -no-hpet -vga cirrus -cpu qemu64,-kvmclock >>>>>>>> >>>>>>>> Exact kernel is: >>>>>>>> 2.6.16.46-0.12-smp (i think this is SLES10 or sth.) >>>>>>>> >>>>>>>> The machine does not hang. It seems just I/O is hanging. So you can type at the console or ping the system, but no longer login. >>>>>>>> >>>>>>>> Thank you, >>>>>>>> Peter >>>>>>> Interesting observation: Migrating the vServer again seems to fix to problem (at least in one case I could test just now). >>>>>>> >>>>>>> 2.6.8-24-smp is also affected. >>>>>> How often does it fail - you say 'sometimes' - is it a 1/10 or a 1/1000 ? >>>>> Its more often than 1/10 I would say. >>>> OK, that's not too bad - it's the 1/1000 that are really nasty to find. >>>> In your setup, how easy would it be for you to try : >>>> with either 2.1 or current head? >>>> with a newer machine-type? >>>> without the cdrom? >>> Its all possible. I can clone the system and try everything on my test systems. I hope >>> it reproduces there. >> Great. I think the order I would go would be: >> Try head - if it works we know we've already got the fix somewhere >> Try 2.1 - if it works we know it's something we introduced between >> 2.1 and 2.2.1 >> Try a newer machine type - because pc-1.2 probably isn't tested much >> CDROM at the end. > > Update: > - head -> not working > - 2.1.3 -> not working > - without CROM -> not working > - with head and no machine type specified -> not working > - with -device isa-ide -> BIOS not booting harddisk > > Will now try 1.3.1 just to be sure. 1.3.1 => not working kernel parameter ide=nodma (ide-core.nodma not supported by kernel) => not working. I usually crash in my setup at around 50-80 migrations. In production it seems to happen more often. Maybe it is load depending. Peter