[dm-devel] problems getting ioband to work properly

[Nikola Ciprich]

Hello all,
I'd like to try I/O shaping using ioband, but it doesn't seem to be working properly for some reason.
I have one disc partition used as LVM PV, VG on top of it. I created two 1GB LVs for tests: iob1, iob2

Then I setup ioband using following commands:

echo 0 2097152 ioband /dev/mapper/vg-iob1 iob 0 0 none weight 0 :40 | dmsetup create ioband-iob1
echo 0 2097152 ioband /dev/mapper/vg-iob2 iob 0 0 none weight 0 :10 | dmsetup create ioband-iob2

When I measure throughput using hdparm --direct -t on one of the ioband devices, i get ~61MBps.

If I measure it on both devices concurrently in loop, throughput settles on ~30MBps on every device, so it seems that it's divided equally.

What am I doing wrong?

thanks a lot in advance

nik

PS: I'm using 2.6.26-rc8+ioband-1.1.0 patch

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Nikola CIPRICH
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