how to disable UTM in SRX

In an SRX device, even if you delete UTM configuration you may still see that control plane memory is
above %80 percent. At least if I take my SRX100 device as an example;

root@srx100-1> show chassis routing-engine
Routing Engine status:
    Temperature                 51 degrees C / 123 degrees F
    Total memory              1024 MB Max   666 MB used ( 65 percent)
      Control plane memory     560 MB Max   454 MB used ( 81 percent)
      Data plane memory        464 MB Max   209 MB used ( 45 percent)

What you can do is to disable UTM system process via the command;

#set system processes utmd disable
#commit and-quit

However disabling this process doesn’t release the memory space immediately. You can reboot the box to gain the
space quickly.

>request system reboot

Then, you have your memory back as seen below!

root@srx100-1> show chassis routing-engine
Routing Engine status:
    Temperature                 50 degrees C / 122 degrees F
    Total memory              1024 MB Max   563 MB used ( 55 percent)
      Control plane memory     560 MB Max   358 MB used ( 64 percent)
      Data plane memory        464 MB Max   209 MB used ( 45 percent)