This question is specifically about Sun X4100, but general information about all servers would be helpful.
This is a 1 rack unit server, and these would typically be placed into a rack with the top facing up, front forward, in the common and intended position.
In some cases however, management wants to store 1 or 2 of these, but they would like to place them with the left side facing up and the right side facing down, or vice-versa.
The airflow would still go out the back. And I don't expect that the law of rising heat is much of a factor with all the fans.
But would there be other problems? For example the hard drives (spinning at 10,000 RPM) might wear on one side of the bearing/axle more than the other side.
I am aware that I am going against the original design of the hardware on this, so I am taking a risk of unexpected hardware failure, but I did want to get your input on this.