Messages in this thread | | | Date | Wed, 30 Jan 2008 12:32:02 +0900 (JST) | Subject | Re: [Xen-devel] dm-band: The I/O bandwidth controller: Performance Report | From | Ryo Tsuruta <> |
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Hi,
> you mean that you run 128 processes on each user-device pairs? Namely, > I guess that > > user1: 128 processes on sdb5, > user2: 128 processes on sdb5, > another: 128 processes on sdb5, > user2: 128 processes on sdb6.
"User-device pairs" means "band groups", right? What I actually did is the followings:
user1: 128 processes on sdb5, user2: 128 processes on sdb5, user3: 128 processes on sdb5, user4: 128 processes on sdb6.
> The second preliminary studies might be: > - What if you use a different I/O size on each device (or device-user pair)? > - What if you use a different number of processes on each device (or > device-user pair)?
There are other ideas of controlling bandwidth, limiting bytes-per-sec, latency time or something. I think it is possible to implement it if a lot of people really require it. I feel there wouldn't be a single correct answer for this issue. Posting good ideas how it should work and submitting patches for it are also welcome.
> And my impression is that it's natural dm-band is in device-mapper, > separated from I/O scheduler. Because bandwidth control and I/O > scheduling are two different things, it may be simpler that they are > implemented in different layers.
I would like to know how dm-band works on various configurations on various type of hardware. I'll try running dm-band on with other configurations. Any reports or impressions of dm-band on your machines are also welcome.
Thanks, Ryo Tsuruta
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