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 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
