I have space reservation disabled on a few LUNs and noticed some strange behavior. As an example, I have a 12TB LUN with 2.2TB of free space, with space reservations disabled. It is on a 13TB volume which currently shows 3.01TB free. The volume is thin provisioned.
If I uncheck the Space Reservation box in System Manager to enable space reservation, I would expect used space to increase in the volume and aggregate, however it only increases in the volume! The volume shows ~790GB free as opposed to 3.01TB since the 2.2TB of LUN free space is now taking up room. However, I don't see a drop of 2.2TB in free space in the aggregate. Why is that? Any ideas?