From df –k command output
apool 4896718848 36 30808623 1% /apool
Here used value figure is 36 (kb) while cdm probe gives the following data as seen in logs
Line 16961: Jul 13 14:59:32:992  cdm: Disk  - disk=/apool val=0(472405)MB avgfree=100%
cdm probe gives output in MB.
If we try to convert 36 kb in MB -> 36/1024, it comes out around 0.035(MB) which on rounding off is not far from 0.
In order to compare the output of probe with df , used figure should be a little high (at least some MBs).