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.
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)?
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.
Regards,
Hiroya.
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