Values of a specific parameter (for example, blkio.throttle.write_bps_device) for all devices are stored in a single file. echo $MAJOR:$MINOR $LIMIT > blkio.throttle.write_bps_device inserts/updates a value to $LIMIT. It does not clear the file, as you might think. So I see no way to delete a value. Also this configuration interface seems to violate the rule one item per file.
How to delete a device parameter for a cgroup?
cgroups;sysfs
I had the same problem, and I found that you have to set $LIMIT to 0 to remove that limit:echo $MAJOR:$MINOR 0 > blkio.throttle.write_bps_deviceThis removes the entry from the cgroup. If you then cat blkio.throttle.write_bps_device, you will not see the entry any more.