[Qemu-devel] Fwd: Re: [RFC 0/7] Migration stats

[Qemu-devel] Fwd: Re: [RFC 0/7] Migration stats

[Chegu Vinod]

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Forwarding to the alias.
Thanks,
Vinod

-------- Original Message --------
Subject: 	Re: [RFC 0/7] Migration stats
Date: 	Mon, 13 Aug 2012 15:20:10 +0200
From: 	Juan Quintela <quintela@redhat.com>
Reply-To: 	<quintela@redhat.com>
To: 	Chegu Vinod <chegu_vinod@hp.com>
CC: 	


[ snip ]

 >> - Prints the real downtime that we have had

>>
>>    really, it prints the total downtime of the complete phase, but the
>>    downtime also includes the last ram_iterate phase.  Working on
>>    fixing that one.

Good one.


[...]

>> What do I want to know:
>>
>> - is there any stat that you want?  Once here, adding a new one should
>>    be easy.
>>

>
> A few suggestions :
>
> a) Total amount of time spent sync'ng up dirty bitmap logs for the
> total duration of migration.

I can add that one, it is not difficult.  Notice that in future I expect
to do the syncs in smaller chucks (but that is pie on the sky)

> b) Actual [average?] bandwidth that was used as compared to the
> allocated bandwidth ...  (I am wanting to know how folks are observing
> near line rate on a 10Gig...when I am not...).

Print average bandwidth is easy.  The "hardware one" is difficult to get
from inside one application.

>
>
>
> 'think it would be useful to know the approximate amount of [host] cpu
> time that got used up by the migration related thread(s) and any
> related host side services (like servicing the I/O interrupts while
> driving traffic through the network). I assume there are alternate
> methods to derive all these (and we don't need to overload the
> migration stats?]

This one is not easy to do from inside qemu.  Much easier to get from
the outside.  As far as I know, it is not easy to monitor cpu usage from
inside the cpu that we can to measure.

Thanks for the comments, Juan.
.





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