* [Qemu-devel] qmp block-mirror hang, lots of nfs op/s on nfs source disk
@ 2015-05-11 11:38 Alexandre DERUMIER
2015-05-11 11:46 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Alexandre DERUMIER @ 2015-05-11 11:38 UTC (permalink / raw)
To: qemu-devel
Hi,
I'm currently playing with drive-mirror, (qemu 2.2)
and I have qmp hang when drive-mirror is starting.
just after qmp "drive-mirror" exec, qmp socket or hmp are not responding.
After some times it's working again, and I can see result of query-block-jobs.
The source volume is on nfs (v4), and it seem that the bigger the volume is, the bigger I need to wait before the mirror begin.
Looking at nfsiostat
op/s rpc bklog
1806.00 0.00
read: ops/s kB/s kB/op retrans avg RTT (ms) avg exe (ms)
0.000 0.000 0.000 0 (0.0%) 0.000 0.000
write: ops/s kB/s kB/op retrans avg RTT (ms) avg exe (ms)
0.000 0.000 0.000 0 (0.0%) 0.000 0.000
I'm seeing a lot of nfs op/s on source disk (but not read).
I wonder if some kind of source file scan is done ? is it expected ?
I can reproduce it 100%
I found a report on redhat bugzilla here, which seem to have same behaviour (not on nfs):
https://bugzilla.redhat.com/show_bug.cgi?id=1185172
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] qmp block-mirror hang, lots of nfs op/s on nfs source disk
2015-05-11 11:38 [Qemu-devel] qmp block-mirror hang, lots of nfs op/s on nfs source disk Alexandre DERUMIER
@ 2015-05-11 11:46 ` Paolo Bonzini
2015-05-11 12:03 ` Alexandre DERUMIER
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2015-05-11 11:46 UTC (permalink / raw)
To: Alexandre DERUMIER, qemu-devel, Fam Zheng
On 11/05/2015 13:38, Alexandre DERUMIER wrote:
> Hi,
>
> I'm currently playing with drive-mirror, (qemu 2.2)
>
> and I have qmp hang when drive-mirror is starting.
>
> just after qmp "drive-mirror" exec, qmp socket or hmp are not
> responding.
>
> After some times it's working again, and I can see result of
> query-block-jobs.
>
>
> The source volume is on nfs (v4), and it seem that the bigger the
> volume is, the bigger I need to wait before the mirror begin.
That is because drive-mirror checks the whole disk for allocated areas.
We are aware of that and Fam (CCed) is working on it. Thanks for the
report nevertheless!
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] qmp block-mirror hang, lots of nfs op/s on nfs source disk
2015-05-11 11:46 ` Paolo Bonzini
@ 2015-05-11 12:03 ` Alexandre DERUMIER
0 siblings, 0 replies; 3+ messages in thread
From: Alexandre DERUMIER @ 2015-05-11 12:03 UTC (permalink / raw)
To: pbonzini; +Cc: Fam Zheng, qemu-devel
>>That is because drive-mirror checks the whole disk for allocated areas.
Oh, ok, that's why I'm seeing a lot of lseek in strace
lseek(21, 1447493632, 0x4 /* SEEK_??? */) = 107374182400
lseek(21, 1447559168, 0x3 /* SEEK_??? */) = 1447559168
lseek(21, 1447559168, 0x4 /* SEEK_??? */) = 107374182400
lseek(21, 1447624704, 0x3 /* SEEK_??? */) = 1447624704
lseek(21, 1447624704, 0x4 /* SEEK_??? */) = 107374182400
lseek(21, 1447690240, 0x3 /* SEEK_??? */) = 1447690240
lseek(21, 1447690240, 0x4 /* SEEK_??? */) = 107374182400
...
>>We are aware of that and Fam (CCed) is working on it. Thanks for the
>>report nevertheless!
Ok, thanks !
----- Mail original -----
De: "pbonzini" <pbonzini@redhat.com>
À: "aderumier" <aderumier@odiso.com>, "qemu-devel" <qemu-devel@nongnu.org>, "Fam Zheng" <famz@redhat.com>
Envoyé: Lundi 11 Mai 2015 13:46:54
Objet: Re: qmp block-mirror hang, lots of nfs op/s on nfs source disk
On 11/05/2015 13:38, Alexandre DERUMIER wrote:
> Hi,
>
> I'm currently playing with drive-mirror, (qemu 2.2)
>
> and I have qmp hang when drive-mirror is starting.
>
> just after qmp "drive-mirror" exec, qmp socket or hmp are not
> responding.
>
> After some times it's working again, and I can see result of
> query-block-jobs.
>
>
> The source volume is on nfs (v4), and it seem that the bigger the
> volume is, the bigger I need to wait before the mirror begin.
That is because drive-mirror checks the whole disk for allocated areas.
We are aware of that and Fam (CCed) is working on it. Thanks for the
report nevertheless!
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-05-11 12:03 UTC | newest]
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2015-05-11 11:38 [Qemu-devel] qmp block-mirror hang, lots of nfs op/s on nfs source disk Alexandre DERUMIER
2015-05-11 11:46 ` Paolo Bonzini
2015-05-11 12:03 ` Alexandre DERUMIER
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