[Question] I have questions about dm-ioband

[Ryo Tsuruta]

Hi Dong-Jae,

From: "Dong-Jae Kang" <baramsori72 at gmail.com>
Subject: Re: [Question] I have questions about dm-ioband
Date: Fri, 7 Nov 2008 16:29:07 +0900

> Hi Ryo Tsuruta
> 
> Thank you very much for your kind and fast reply
> 
> 2008/11/7 Ryo Tsuruta <ryov at valinux.co.jp>:
> > Hi Dong-Jae,
> >
> > From: "Dong-Jae Kang" <baramsori72 at gmail.com>
> > Subject: [Question] I have questions about dm-ioband
> > Date: Fri, 7 Nov 2008 14:39:56 +0900
> >
> >> Hi, Ryo tsuruta
> >>
> >> During past several days, I had been analyzing and testing your
> >> dm-ioband I/O controller.
> >> because I received some requirements about disk I/O control from other
> >> persons as below
> >> "guaranteeing the minimum BW of processes in the specific group", of
> >> course, in the total BW range.
> >> I think it can be adjusted to streaming service, SLA of service
> >> hosting part and so on.
> >> although the applicable area is some specific and limited part, it can
> >> be useful according to the service
> >> How do you think about upper requirement?
> >
> > I think I know why they want minimum bandwidth guarantee and it
> > would be useful on a certain situation.
> >
> >> If it is required, I think that try to support the function in your
> >> dm-ioband controller
> >> personally, I like your design and implementation style.
> >> And, for it , where is the appropriate part in dm-ioband controller to
> >> implement the function?
> >> Can you give me some advice and comments about supporting it ?
> >
> > Sure! dm-ioband is designed to be able to add new bandwidth control
> > policies. dm-ioband-policy.c is a source code of "weight" and
> > "weight-iosize" policies, and would help to understand how to add
> > a new policy.
> >
> 
> OK, I will start to analyze the dm-ioband-policy.c first.
> during the job, if I have a another question or need your help, can I
> ask you about it?
> Thank you.

Of course you can.

> >> I don't know well about the details of dm-ioband controllers, concept,
> >> design, architecture and so on.
> >> it will take some time for me to do that ^^
> >> Well, Is there any documentations to help for me to understand the
> >> existing implementation ?
> >> If so, can I refer it ?
> >
> > Sorry, there is no document which describes the implementation.
> >
> Oh.... I should put up with inconvenience. ㅜㅜ
> but, I still appreciate your contribution for OSS community
> 
> >> additional one question is left^^
> >> dm-ioband can be operated with another dm targets at the same thme?
> >> with such like multipath, mirror, linear, snapshot and something like that.
> >> for example, IO control over the mirror targets or IO control over the
> >> devices with multipath, ....
> >
> > I have run dm-ioband on a logical volume disk and it worked well.
> > http://people.valinux.co.jp/~ryov/dm-ioband/benchmark/lvm.html
> >
> 
> I understood
> You mean dm-ioband can run over another dm targets.

I have just tested with LVM, not with other targets ever.

> Thank you again
> -- 
> Best Regards,
> Dong-Jae Kang

Thanks,
Ryo Tsuruta