Minor nit, but that should be:

isilon# isi get -D

if, for instance, you wanted to look at inode information like disk pool affiliation and what is planned for the file.

If you wanted to look at the actual placement of blocks on the Isilon, then:

isilon# isi get -DD | less

will list the same as the single -D (the inode information), plus it will list all the "stripes" of the file at the end of the list, which can be quite large if it's a big file.  For instance, you'll see chunks of data like this:

       lbn 35200: 4+2/2

                2,10,27780055040:8192#16

                2,7,27873476608:8192#16

                3,10,28058181632:8192#16

                3,8,28000976896:8192#16

                1,7,31293358080:8192#16

                1,8,31316877312:8192#16

Decoded, this is:

NodeID,Drive, : #

Using this information, you can tell with certainty where data for the file actually resides.