Configure block device IO rate

Configure block device IO rate

[aragrawal]

Hi

I am interested in getting the block I/O rate fixed for a Virtual 
Machine. However, it seems that there are no such options to control the 
block I/O rate via the VM configuration file.
Going through the net, I see suggestions to configure the xen_blkback 
driver using ionice to get that done.

I would like to know if there are any plans to include any such 
configuration option.
Also, are there any particular reason (apart from the fact that there 
are other ways to get this done) for the absence of such configuration 
option?


Thanks
Ankit Agrawal

Re: Configure block device IO rate

[George Dunlap]

On Mon, Nov 24, 2014 at 3:54 AM, aragrawal <aragrawal@cs.wisc.edu> wrote:
> Hi
>
> I am interested in getting the block I/O rate fixed for a Virtual Machine.
> However, it seems that there are no such options to control the block I/O
> rate via the VM configuration file.
> Going through the net, I see suggestions to configure the xen_blkback driver
> using ionice to get that done.
>
> I would like to know if there are any plans to include any such
> configuration option.
> Also, are there any particular reason (apart from the fact that there are
> other ways to get this done) for the absence of such configuration option?

I'm pretty sure it's just because nobody had asked for it yet.

We can put it on our list of things to think about doing / projects
for people new to the community.

We also accept patches. :-)

 -George

Re: Configure block device IO rate

[Konrad Rzeszutek Wilk]

On Mon, Nov 24, 2014 at 12:07:39PM +0000, George Dunlap wrote:
> On Mon, Nov 24, 2014 at 3:54 AM, aragrawal <aragrawal@cs.wisc.edu> wrote:
> > Hi
> >
> > I am interested in getting the block I/O rate fixed for a Virtual Machine.
> > However, it seems that there are no such options to control the block I/O
> > rate via the VM configuration file.
> > Going through the net, I see suggestions to configure the xen_blkback driver
> > using ionice to get that done.
> >
> > I would like to know if there are any plans to include any such
> > configuration option.
> > Also, are there any particular reason (apart from the fact that there are
> > other ways to get this done) for the absence of such configuration option?
> 
> I'm pretty sure it's just because nobody had asked for it yet.
> 
> We can put it on our list of things to think about doing / projects
> for people new to the community.
> 
> We also accept patches. :-)

Patches for this were in the past posted - it just that nobody explained
to the maintainer (me) why the dm-* or io-nice would not do the same job.

I sadly don't remember from whom they were or such.
> 
>  -George
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Re: Configure block device IO rate

[Ian Campbell]

On Mon, 2014-11-24 at 10:06 -0500, Konrad Rzeszutek Wilk wrote:
> On Mon, Nov 24, 2014 at 12:07:39PM +0000, George Dunlap wrote:
> > On Mon, Nov 24, 2014 at 3:54 AM, aragrawal <aragrawal@cs.wisc.edu> wrote:
> > > Hi
> > >
> > > I am interested in getting the block I/O rate fixed for a Virtual Machine.
> > > However, it seems that there are no such options to control the block I/O
> > > rate via the VM configuration file.
> > > Going through the net, I see suggestions to configure the xen_blkback driver
> > > using ionice to get that done.
> > >
> > > I would like to know if there are any plans to include any such
> > > configuration option.
> > > Also, are there any particular reason (apart from the fact that there are
> > > other ways to get this done) for the absence of such configuration option?
> > 
> > I'm pretty sure it's just because nobody had asked for it yet.
> > 
> > We can put it on our list of things to think about doing / projects
> > for people new to the community.
> > 
> > We also accept patches. :-)
> 
> Patches for this were in the past posted - it just that nobody explained
> to the maintainer (me) why the dm-* or io-nice would not do the same job.

AIUI the question here is why the toolstack doesn't integrate a guest
cfg file setting to configure dm-* and/or io-nice, rather than why
blkback doesn't duplicate their functionality.

Ian.

Re: Configure block device IO rate

[Konrad Rzeszutek Wilk]

On Mon, Nov 24, 2014 at 03:11:20PM +0000, Ian Campbell wrote:
> On Mon, 2014-11-24 at 10:06 -0500, Konrad Rzeszutek Wilk wrote:
> > On Mon, Nov 24, 2014 at 12:07:39PM +0000, George Dunlap wrote:
> > > On Mon, Nov 24, 2014 at 3:54 AM, aragrawal <aragrawal@cs.wisc.edu> wrote:
> > > > Hi
> > > >
> > > > I am interested in getting the block I/O rate fixed for a Virtual Machine.
> > > > However, it seems that there are no such options to control the block I/O
> > > > rate via the VM configuration file.
> > > > Going through the net, I see suggestions to configure the xen_blkback driver
> > > > using ionice to get that done.
> > > >
> > > > I would like to know if there are any plans to include any such
> > > > configuration option.
> > > > Also, are there any particular reason (apart from the fact that there are
> > > > other ways to get this done) for the absence of such configuration option?
> > > 
> > > I'm pretty sure it's just because nobody had asked for it yet.
> > > 
> > > We can put it on our list of things to think about doing / projects
> > > for people new to the community.
> > > 
> > > We also accept patches. :-)
> > 
> > Patches for this were in the past posted - it just that nobody explained
> > to the maintainer (me) why the dm-* or io-nice would not do the same job.
> 
> AIUI the question here is why the toolstack doesn't integrate a guest
> cfg file setting to configure dm-* and/or io-nice, rather than why
> blkback doesn't duplicate their functionality.

Ah, that is a different question. That certainly could be done by somebody
who has the time.
> 
> Ian.
> 
> 

Re: Configure block device IO rate

[Ankit Agrawal]

On 11/24/2014 09:20 AM, Konrad Rzeszutek Wilk wrote:
> On Mon, Nov 24, 2014 at 03:11:20PM +0000, Ian Campbell wrote:
>> On Mon, 2014-11-24 at 10:06 -0500, Konrad Rzeszutek Wilk wrote:
>>> On Mon, Nov 24, 2014 at 12:07:39PM +0000, George Dunlap wrote:
>>>> On Mon, Nov 24, 2014 at 3:54 AM, aragrawal <aragrawal@cs.wisc.edu> wrote:
>>>>> Hi
>>>>>
>>>>> I am interested in getting the block I/O rate fixed for a Virtual Machine.
>>>>> However, it seems that there are no such options to control the block I/O
>>>>> rate via the VM configuration file.
>>>>> Going through the net, I see suggestions to configure the xen_blkback driver
>>>>> using ionice to get that done.
>>>>>
>>>>> I would like to know if there are any plans to include any such
>>>>> configuration option.
>>>>> Also, are there any particular reason (apart from the fact that there are
>>>>> other ways to get this done) for the absence of such configuration option?
>>>> I'm pretty sure it's just because nobody had asked for it yet.
>>>>
>>>> We can put it on our list of things to think about doing / projects
>>>> for people new to the community.
>>>>
>>>> We also accept patches. :-)
>>> Patches for this were in the past posted - it just that nobody explained
>>> to the maintainer (me) why the dm-* or io-nice would not do the same job.
>> AIUI the question here is why the toolstack doesn't integrate a guest
>> cfg file setting to configure dm-* and/or io-nice, rather than why
>> blkback doesn't duplicate their functionality.
> Ah, that is a different question. That certainly could be done by somebody
> who has the time.
>> Ian.
>>
>>
Hi

Thanks for the quick reply. I see the time constraint is the only issue 
here.

Regards
Ankit Agrawal