vertical or horizontal ? RACK EIII

[DARKSHINE]

currently my EIII rack is horizontal, I would like to change to the vertical,  it is safe? 

vertical like this : http://www.tandy-electronique.com/support-pour-accessoires-rack-p-1365.html

[wirefall]

Be careful with your hard disk. If it has run in one specific position all the time over years, it wouldn't be a good idea to run it now in another orientation. A hard disk, even an old one, could crash then. But maybe this is a good reason to change the hard disk with a CF card solution