7914DS3KPlanning_090710.fm Draft Document for Review March 28, 2011 12:24 pm
34  IBM System Storage DS3500: Introduction and Implementation Guide
Create a floor plan to check for clearance problems. Be sure to include the following 
considerations in the layout plan:
ň° Determine service clearances required for each rack or suite of racks.
ň° If the equipment is on a raised floor, determine:
â The height of the raised floor
â Things that might obstruct cable routing
ň° If the equipment is not on a raised floor, determine:
â The placement of cables to minimize obstruction
â If the cable routing is indirectly between racks (such as along walls or suspended), the 
amount of additional cable needed
â Cleanliness of floors, so that the fan units will not attract foreign material such as dust 
or carpet fibers
ň° Determine the location of:
â Power receptacles
â Air conditioning equipment, placement of grilles, and controls
â File cabinets, desks, and other office equipment
â Room emergency power-off controls
â All entrances, exits, windows, columns, and pillars
â Fire control systems
ň° Check access routes for potential clearance problems through doorways and passage 
ways, around corners, and in elevators for racks and additional hardware that will require 
installation.
ň° Store all spare materials that can burn in properly designed and protected areas.
Rack layout
To be sure that you have enough space for the racks, create a floor plan before installing the 
racks. You might need to prepare and analyze several layouts before choosing the final plan.
If you are installing the racks in two or more stages, prepare a separate layout for each stage.
The following considerations apply when you make a layout:
ň° The flow of work and personnel within the area
ň° Operator access to units, as required
ň° If the rack is on a raised floor, determine:
â The need for adequate cooling and ventilation
ň° If the rack is not on a raised floor, determine:
â The maximum cable lengths
â The need for cable guards, ramps, and so on to protect equipment and personnel
ň° Location of any planned safety equipment
ň° Future expansion
Review the final layout to ensure that cable lengths are not too long and that the racks have 
enough clearance.
You need at least 152 cm (60 in.) of clearance at the front and at least 76 cm (30 in.) at the 
rear of the 42U rack suites. This space is necessary for opening the front and rear doors and 
for installing and servicing the rack. It also allows air circulation for cooling the equipment in 
the rack. All vertical rack measurements are given in rack units (U). One U is equal to 4.45 cm