From: Peter Lieven <pl@dlh.net>
To: Shu Ming <shuming@linux.vnet.ibm.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] Stalls on Live Migration of VMs with a lot of memory
Date: Wed, 04 Jan 2012 11:53:21 +0100 [thread overview]
Message-ID: <4F042FA1.5090909@dlh.net> (raw)
In-Reply-To: <4F03AD98.7020700@linux.vnet.ibm.com>
On 04.01.2012 02:38, Shu Ming wrote:
> On 2012-1-4 2:04, Peter Lieven wrote:
>> Hi all,
>>
>> is there any known issue when migrating VMs with a lot of (e.g. 32GB)
>> of memory.
>> It seems that there is some portion in the migration code which takes
>> too much time when the number
>> of memory pages is large.
>>
>> Symptoms are: Irresponsive VNC connection, VM stalls and also
>> irresponsive QEMU Monitor (via TCP).
>>
>> The problem seems to be worse on 10G connections between 2 Nodes (i
>> already tried limiting the
>> bandwidth with the migrate_set_speed command) than on 1G connections.
> Is the migration accomplished finally? How long will that be? I did
> a test on VM with 4G and it took me about two seconds.
it seems that the majority of time (90%) is lost in:
cpu_physical_memory_reset_dirty(current_addr,
current_addr +
TARGET_PAGE_SIZE,
MIGRATION_DIRTY_FLAG);
anyone any idea, to improve this?
next prev parent reply other threads:[~2012-01-04 10:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-03 18:04 [Qemu-devel] Stalls on Live Migration of VMs with a lot of memory Peter Lieven
2012-01-04 1:38 ` Shu Ming
2012-01-04 9:11 ` Peter Lieven
2012-01-04 10:53 ` Peter Lieven [this message]
2012-01-04 11:05 ` Paolo Bonzini
2012-01-04 11:22 ` Peter Lieven
2012-01-04 11:28 ` Paolo Bonzini
2012-01-04 11:42 ` Peter Lieven
2012-01-04 12:28 ` Paolo Bonzini
2012-01-04 13:08 ` Peter Lieven
2012-01-04 14:14 ` Paolo Bonzini
2012-01-04 14:17 ` Peter Lieven
2012-01-04 14:21 ` Peter Lieven
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