if hvm better than pv?why dd in hvm vm no larger than 50M, while pv greater than 50

if hvm better than pv?why dd in hvm vm no larger than 50M, while pv greater than 50

[yue]

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1.if passthrough pci  is default in hvm?  pv disk throughput better than hvm,using dd test
thanks

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Re: if hvm better than pv?why dd in hvm vm no larger than 50M, while pv greater than 50

[Konrad Rzeszutek Wilk]

On Sat, Apr 23, 2011 at 03:47:23PM +0800, yue wrote:
> 1.if passthrough pci  is default in hvm?  pv disk throughput better than hvm,using dd test
> thanks

Please write your question more clearly. I am having a hard time understanding what it
is that you are asking.

Re:Re: if hvm better than pv?why dd in hvm vm no larger than 50M, while pv greater than 50

[yue]

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1.i find  pv disk'throughput is better than hvm. i want to know why?
2.pci passthrough  is said to improve performance, if it is default method of IO-process.
 3.do you familar with ocfs2's source code?
 
thanks




At 2011-04-25 21:36:04，"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com> wrote:

>On Sat, Apr 23, 2011 at 03:47:23PM +0800, yue wrote:
>> 1.if passthrough pci  is default in hvm?  pv disk throughput better than hvm,using dd test
>> thanks
>
>Please write your question more clearly. I am having a hard time understanding what it
>is that you are asking.
>
>_______________________________________________
>Xen-devel mailing list
>Xen-devel@lists.xensource.com
>http://lists.xensource.com/xen-devel

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Re: Re: if hvm better than pv?why dd in hvm vm no larger than 50M, while pv greater than 50

[Konrad Rzeszutek Wilk]

On Tue, Apr 26, 2011 at 04:48:31PM +0800, yue wrote:
> 1.i find  pv disk'throughput is better than hvm. i want to know why?

Pick up "The definitive guide to the Xen hypervisor" book.
> 2.pci passthrough  is said to improve performance, if it is default method of IO-process.

Sure. But it also makes migration difficult.
>  3.do you familar with ocfs2's source code?

No.