I am seeing the same disk space issue as described in original post.

Each partition is about 8GB, total 14 partitions. each partition about 50M rows.

The cube was processed before so it exists with about 110GB total used space.

Free space about 200GB.

When re-processing the same cube, the free space seems to slowly disappear, for example only after processing 2 partitions, the free space went from 200GB to 40GB. This is while the total used space in this cube directory is 120GB. The used space makes sense - 110GB + 8G for 2nd copy of partition that's being processed.

The free space gone to neverland is what doesn't make sense!

I am processing partitions from BIDS (highlighted all partitions). Processing each partition separately, each with its own transaction.

I've seen the same type of Disk space stealing by SSAS server when for example deleting a cube. Somehow when I delete the cube, it does not show that disk space is free, while the files are gone!, - that is until you restart SSAS server.

can anyone shed a light on this?

(win 2003 ent, sql 2005 ent sp2 fin, 32 bit, 16gb ram, 4 cpu)

Does SSAS actually use the Disk for temporary cache of data during aggregation?

can anyone from MS SSAS team clarify?

if that's true, which "directory" is it, and can I change it to be a different disk? I so happen to have more free space available on a different drive (not OLAP Data drive).

any ideas?

I guess this should be filed as a bug. what should I call this bug? "space stealing?"