[rhelv6-list] testing control groups... how to reset a previously set value limit?

[Gianluca Cecchi]

Hello,
I'm testing some control groups features on a rh el 6.2 host as
hypervisor and their effects inside one of its vms named testvm

vm insists on some multipath devices on host, so 253:N devices. I want
to limit I/O and run:

echo "253:0 5000000" >
/cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device
echo "253:1 5000000" >
/cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device
echo "253:2 5000000" >
/cgroup/blkio/libvirt/qemutestvm/blkio.throttle.write_bps_device
echo "253:3 5000000" >
/cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device
echo "253:5 5000000" >
/cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device
echo "253:6 5000000" >
/cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device


On hypervisor:
# cgget -r blkio.throttle.read_bps_device libvirt/qemu/testvm
libvirt/qemu/testvm:
blkio.throttle.read_bps_device: 253:6	5000000
	253:5	5000000
	253:3	5000000
	253:2	5000000
	253:1	5000000
	253:0	5000000

Now if I want to reset the values for blkio.throttle.write_bps_device
to their original ones (so no limit), to have

# cat /cgroup/blkio/libvirt/qemu/testvm/blkio.throttle.write_bps_device

that returns no value, which syntax can I use?

Thanks in advance,
Gianluca