Memory consumption after turning off dedup

[David Wimsey]

I've had dedup on for a while and everything was good until the feeble machine I have as a file server couldn't deal with the memory requirements of dedup.  I solved the problem by adding more RAM, imported the pools on the machine and turned off dedup.  I had a ratio of less than 2x, and the main savings were on virtual machine disks which I want maximum performance for.

Does the memory consumption due to the DDT go away when you turn dedup off or do I need to do a send/recv on it?

I assume that once the block is deduced and written to disk its not really any different than a blocks associated with a snapshot, is that correct?

I also assume that there is no performance penalties on reads, only writes since it (with dedup on) has to check the dedup table to see if it is a duplicate, is that correct?