Re: [Qemu-block] virtio-scsi and request splitting

[Paolo Bonzini]

On 01/06/2017 15:30, Peter Lieven wrote:
> Hi,
> 
> 
> i noticed a while ago that if I start a job like this in a vserver:
> 
> dd if=/dev/zero of=/x bs=1M count=128 oflag=direct
> 
> I see each of the 1M request splitted into 516096 + 516096 + 16384 bytes
> with virtio-scsi
> 
> If I use virtio-blk the request goes through with 1M size.
> 
> Any idea whats the cause of this?

It may depend on memory fragmentation.

Paolo