Does a Compellent SC40 zero out "unused" data?

Hey all -

I was just wondering if the data reduction (deduplication) feature on the Compellent might cause it to zero out data on a freshly-formatted LVM partition, or if it will leave data written to the actual disk blocks alone there. Also, where would I go and check to see if data reduction (deduplication) is enabled or disabled in Storage Manager software version 6.6.5?