Determining rack locations
The appliance and the storage shelves are both two rack units (2RU) high. To help you identify RU spacing, many rack manufacturers typically use a system of lines and sequential numbers starting at the bottom of the rack. The front and the rear of the rack are marked the same to ensure that the rails are installed straight and level. One RU has three holes. The holes for one RU are typically marked with a line below the bottom hole and another line above the top hole.
Next, use the rack templates that ship with the storage shelves to determine the mounting locations.
See Best practices for rack installation.
To determine rack locations for the storage shelves
- A storage shelf is 2RU high. Multiply the number 2 by the number of shelves that you plan to install.
An appliance and six storage shelves require a total of 14 RUs.
- Use the rack templates that are provided with the hardware to determine RU locations. The templates show the front and rear of a storage shelf in a rack.
- Fold the template along the yellow dotted lines to match the rack holes exactly.
- Record the rack positions to help you locate them easily when mounting the hardware.
- Next, assess the SAS-3 cables to be sure that you have the correct lengths for your installation.
The following procedure provides information to help you verify that you have the correct lengths of SAS-3 cable.
To determine SAS-3 cable requirements
- Note that each rack unit (RU) is 44.50 mm (1.752 inches) in height. The 5250 Appliance and the 5250 Storage Shelf are both 2RU high.
- Each SAS-3 cable is 1 meter (3.28 feet) long. The 1-meter cable is long enough to connect an appliance to the fourth storage shelf, assuming that the recommended configuration is used.
Verify that your cables are long enough to connect all of the devices.
Longer SAS-3 cables are supported with the 2U12 Storage Shelf if needed for the configuration and are provided by the customer.