HPE MSA 1050

Testing enclosure connections 21
The diagram at right (above) shows the same storage components connected using straight-through cabling. Using this
method, if a drive enclosures fails, the enclosures that follow the failed enclosure in the chain are no longer accessible
until the failed enclosure is repaired or replaced.
Figure 11 (page 20) provides example diagrams reflecting fault-tolerant (left) and straight-through (right) cabling for the
maximum number of supported MSA 1050 enclosures (four enclosures including the controller enclosure).
IMPORTANT: For comprehensive configuration options and associated illustrations, refer to the HPE MSA 1050 Cable
Configuration Guide.
Testing enclosure connections
NOTE: Once the power-on sequence for enclosures succeeds, the storage system is ready to be connected to hosts, as
described in “Connecting the enclosure to data hosts” (page 23).
Powering on/powering off
Before powering on the enclosure for the first time:
• Install all disk drives in the enclosure so the controller can identify and configure them at power-up.
• Connect the cables and power cords to the enclosures as explained in the quick start instructions.
NOTE: Power supplies used in MSA 1050 enclosures
The MSA 1050 controller enclosures and drive enclosures are equipped with AC power supplies that do not have power
switches (they are switchless). They power on when connected to a power source, and they power off when disconnected.
• When powering up, make sure to power up the enclosures and associated host in the following order:
 Drive enclosures first
This ensures that disks in each drive enclosure have enough time to completely spin up before being scanned by
the controller modules within the controller enclosure.
While enclosures power up, their LEDs blink. After the LEDs stop blinking—if no LEDs on the front and back of
the enclosure are amber—the power-on sequence is complete, and no faults have been detected. See “LED
descriptions” (page 57) for descriptions of LED behavior.
 Controller enclosure next
Depending upon the number and type of disks in the system, it may take several minutes for the system to
become ready.
 Hosts last (if powered down for maintenance purposes)
TIP: When powering off, you will reverse the order of steps used for powering on.
IMPORTANT: See “Power cord requirements” (page 70) and the QuickSpecs for more information about power cords
supported by MSA 1050 enclosures.