NDMPcopy which is available on the Celerra Tools and Apps CD can be used to Copy From Celerra B LargeFS to Celerra B SmallFS while preserving deduplicated data.    Mike McKay EMC Corporation Mobile: 201-704-9947 Email: mike.mckay[NAME].com
Let me first start by saying that I know that once you extend a file system, you can not "shrink" it. I did find this article which told of a workaround which seems like it would give you the same result though:[URL]  Here is my dilema. I have a 1Tb file system that I am copying from one Celerra to another. The source Celerra has dedupe enabled on the File System, so the 1Tb of data has been shrunk to 500Gb. In order for me to copy that to the target Celerra, I have to create a 1Tb file system on the target for it to move to because when it is copying, it copies the files in their original sizes. So once the file system has been copied from Celerra A to Celerra B, I am left with 1Tb of data that has not yet been deduped. I can let dedupe run on the file system on Celerra B, and the 1Tb of data will eventually compress down to 500Gb. The problem with the procedure in the link above is that when it is on Celerra B, and I create a second smaller file system to move the data to, it will "rehydrate" the files again when I go from the larger file system to the smaller one, and I am back in the same boat. I am just wondering if there is a workaround to this that anyone can think of? One method would be to create a small file system on Celerra B, and copy the data in small chunks, let dedupe run, then copy some more, let dedupe run, copy more, etc etc. That would just take a lot of time though. Any other thoughts? 
"Shrinking" a file system with deduplication enabled