User guide

Rack information C–17
Hitachi Unified Storage VM Block Module Hardware User Guide
• In an enclosed rack with a ventilation fan in the top, excessive heat
generated by equipment near the bottom of the rack can be drawn
upward and into the intake ports of the equipment above it in the rack.
Ensure that you provide adequate ventilation for equipment at the
bottom of the rack.
Height considerations
Rack-mount storage (or server) chassis (devices) are measured in “U's,”
which is short for “units” and refers to a standard for measuring the height
of a device when installed into a rack. A 1U server, for example, is very thin,
measuring only 1.75" high, while 2U is 3.5", exactly double the height of
1U. The Hitachi rack is a 42U rack.
To reduce the risk of injury to persons or damage to the storage system,
review the following guidelines prior to installing the HUS VM system into
the Hitachi rack.
• Install the anti-tip stabilizing plate to provide added stability during
installation. See Stabilizing the rack on page C-30 and Installing side
stabilizer plates. Figure C-19: Installing and Uninstalling the Anti-Tip
Stabilizing Plate (2) on page C-33 shows an example of how to install
the side stabilizer plates.
• Obtain assistance to lift and stabilize the product during installation or
removal, especially when the product is not yet fastened to the rails.
• Use stable mechanical lift equipment that can handle the weight and that
can lift components to the highest levels of the rack (70-80 inches).
• When using a mechanical lift device, do not move it away from the rack
frame or lower the platform until the red line on the label affixed to the
HUS VM system has crossed the front of the rail kit. Otherwise, the HUS
VM system may fall.
• Install equipment with at least one other person.
• Remove all pluggable power supplies and modules to reduce total
product weight before lifting it.
• Observe local occupational health and safety requirements and
guidelines for manual material handling.
• The handles may be used when raising the HUS VM system, but it is
preferable to hold it by the front and rear portions made of sheet metal.
• Be sure that there are no scratches or flaws on the power cables. These
defects may cause electric shock or a fire.
• Be sure the storage units are connected to a properly grounded power
source to prevent electric shock.
• When mounting the heaviest equipment at the bottom of a Hitachi rack
and the lightest equipment at the top, keep the center of mass at or
below the 20 U line.
Note: Hitachi racks have a maximum mountable space of 42U. 2U is
reserved at the base of the rack. The HUS VM base and drive boxes are
mounted starting from that point in the rack.