[pve-devel] Baloon Device is the problem! Re: migration problems since qemu 1.3

Alexandre DERUMIER aderumier at odiso.com
Wed Dec 26 17:40:59 CET 2012


the migrate_downtime = 1, come from QemuServer.pm


    migrate_downtime => {
        optional => 1,
        type => 'integer',
        description => "Set maximum tolerated downtime (in seconds) for migrations.",
        minimum => 0,
        default => 1,  >>>>>>DEFAULT VALUE
    },


I don't know if we really need a default value, because it's always setting migrate_downtime to 1. 


Now, I don't know what really happen to you, because recent changes can set migrate_downtime to the target vm (vm_mon_cmd_nocheck) 
But I don't think it's doing something because the migrate_downtime should be done one sourcevm.

Can you try to replace vm_mon_cmd_nocheck by vm_mon_cmd ? (So it should works only at vm_start but not when live migrate occur on target vm)


also migrate_downtime, should be set on sourcevm before the migration begin (QemuMigrate.pm). I don't know why we are setting it at vm start.


----- Mail original ----- 

De: "Stefan Priebe" <s.priebe at profihost.ag> 
À: "Alexandre DERUMIER" <aderumier at odiso.com> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Mercredi 26 Décembre 2012 13:18:33 
Objet: Re: [pve-devel] Baloon Device is the problem! Re: migration problems since qemu 1.3 

Hi, 

the difference is in sub vm_start in QemuServer.pm. After the kvm 
process is started PVE sends some human monitor commands. 

If i comment this line: 
# eval { vm_mon_cmd_nocheck($vmid, "migrate_set_downtime", 
value => $migrate_downtime); }; 

Everything works fine and everything is OK again. 

I also get this in my logs but i checked $migrate_downtime is 1 so it IS 
a NUMBER: 

Dec 26 13:09:27 cloud1-1202 qm[8726]: VM 105 qmp command failed - VM 105 
qmp command 'migrate_set_downtime' failed - Invalid parameter type for 
'value', expected: number 

Stefan 
Am 26.12.2012 07:45, schrieb Alexandre DERUMIER: 
>>> I can even start it with daemonize from shell. Migration works fine. It 
>>> just doesn't work when started from PVE. 
> This is crazy .... I don't see any difference from starting it from shell or from pve.... 
> 
> And if your remove the balloon device, migration is 100% working, starting from pve ? 
> 
> just to be sure, can you try to do "info balloon" from human monitor console ? (I would like to see if the balloon driver is correctly working) 
> 
> 
> ----- Mail original ----- 
> 
> De: "Stefan Priebe" <s.priebe at profihost.ag> 
> À: "Alexandre DERUMIER" <aderumier at odiso.com> 
> Cc: pve-devel at pve.proxmox.com 
> Envoyé: Mardi 25 Décembre 2012 10:05:10 
> Objet: Re: [pve-devel] Baloon Device is the problem! Re: migration problems since qemu 1.3 
> 
> I can even start it with daemonize from shell. Migration works fine. It 
> just doesn't work when started from PVE. 
> 
> Stefan 
> 
> Am 24.12.2012 15:48, schrieb Alexandre DERUMIER: 
>> does it work if you keep device virtio-balloon enabled, 
>> 
>> but comment in qemuserver.pm 
>> 
>> line 3005 
>> vm_mon_cmd_nocheck($vmid, 'qom-set', 
>> path => "machine/peripheral/balloon0", 
>> property => "stats-polling-interval", 
>> value => 2); 
>> 
>> 
>> and 
>> 
>> line2081 
>> $qmpclient->queue_cmd($vmid, $ballooncb, 'query-balloon'); 
>> 
>> ? 
>> 
>> ----- Mail original ----- 
>> 
>> De: "Alexandre DERUMIER" <aderumier at odiso.com> 
>> À: "Stefan Priebe" <s.priebe at profihost.ag> 
>> Cc: pve-devel at pve.proxmox.com 
>> Envoyé: Lundi 24 Décembre 2012 15:38:13 
>> Objet: Re: [pve-devel] Baloon Device is the problem! Re: migration problems since qemu 1.3 
>> 
>> maybe it's related to qmp queries to balloon driver (for stats) during migration ? 
>> 
>> 
>> 
>> ----- Mail original ----- 
>> 
>> De: "Stefan Priebe" <s.priebe at profihost.ag> 
>> À: "Dietmar Maurer" <dietmar at proxmox.com> 
>> Cc: "Alexandre DERUMIER" <aderumier at odiso.com>, pve-devel at pve.proxmox.com 
>> Envoyé: Lundi 24 Décembre 2012 15:32:52 
>> Objet: Baloon Device is the problem! Re: [pve-devel] migration problems since qemu 1.3 
>> 
>> Hello, 
>> 
>> it works fine / again if / when i remove the baloon pci device. 
>> 
>> If i remove this line everything is fine again! 
>> -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 
>> 
>> Greets 
>> Stefan 
>> Am 24.12.2012 15:05, schrieb Stefan Priebe: 
>>> 
>>> Am 24.12.2012 14:08, schrieb Dietmar Maurer: 
>>>>> virtio0: 
>>>>> cephkvmpool1:vm-105-disk- 
>>>>> 1,iops_rd=215,iops_wr=155,mbps_rd=130,mbps_wr=90,size=20G 
>>>> 
>>>> Please can you also test without ceph? 
>>> 
>>> The same. I now also tried a debian netboot cd (6.0.5) but then 32bit 
>>> doesn't work too. I had no disks attached at all. 
>>> 
>>> I filled the tmpfs ramdisk under /dev with 
>>> dd if=/dev/urandom of=/dev/myfile bs=1M count=900 
>>> 
>>> Greets, 
>>> Stefan 
>> _______________________________________________ 
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>> pve-devel at pve.proxmox.com 
>> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel 
>> 



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