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Date: Tue, 21 Apr 2015 12:53:32 +0300
From: Konstantin Krotov <kkv@clodo.ru>
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Subject: Re: [Qemu-devel] virtio-blk and virtio-scsi performance comparison
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To: Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <famz@redhat.com>
Cc: qemu-devel@nongnu.org



16.04.2015 14:57, Paolo Bonzini пишет:
>
> On 16/04/2015 13:17, Konstantin Krotov wrote:
>> In my production system i'm interested to use io=thread, becouse i
>> export MD raid1 devices to guest's and i need to read from the MD device
>> performs balanced between raid1 legs (it's true only if io=thread).
>
> Can you detail the problem more?  That could be a kernel bug.
>
> Paolo
>

I connect to the host system, two storage systems as block devices. Both 
block devices combine md-raid1. md-device use as disk for virtual 
machine. If i use io=native, read perform only from one of two raid1 
legs. I'd like to distribute the load reading between two raid1 legs, 
but md-raid1 implementation it does only if set io=thread.

-- 
WBR
Konstantin V. Krotov