They are forcing the air along the gaps existing between drive columns out the back. As you can see, the gaps between the columns are fairly narrow, so air is moving *quickly* along the disks. Having the top cover (not shown in the picture) in place is important for the system's cooling, so that the air taken in by the fans along the front has no place to go except between the disk columns, and out the back.
Slashdot Mirror
Have you seen the array of fans on the front of the system?
h e_rise_of_the_general
http://blogs.sun.com/roller/page/jonathan?entry=t
They are forcing the air along the gaps existing between drive columns out the back.
As you can see, the gaps between the columns are fairly narrow, so air is moving
*quickly* along the disks. Having the top cover (not shown in the picture) in place
is important for the system's cooling, so that the air taken in by the fans along the front
has no place to go except between the disk columns, and out the back.