IBM eX5 Implementation Guide

Chapter 6. IBM System x3850 X5 and x3950 X5 249

installed in the server. To control the boot sequence, from within F1-Setup, select System

Settings  Device and I/O Protest Option ROM Execution Order. Figure 6-25 shows what

the panel looks like after pressing Enter on the list of possible choices. Use the up and down

arrow keys to select a specific entry to move and use the plus or minus keys to move the item

up or down the list.

Figure 6-25 Set Option ROM Execution Order maintenance panel

6.7 Power supply considerations

Most models of the System x3850 X5 ship with two power supplies that will support the entire

server with redundant power regardless of the configuration.

When the server loses one of the two power supplies, the server will report the following

warning in the system event log:

“Non-redundant: Sufficient Resources for Redundancy Degraded”

The MAX5 also comes with two power supplies. If power fails in the MAX5, the server will

power off. Powering the server back on will not be possible unless the MAX5 has power or

until both QPI cables have been disconnected from the server, after removing ac power from

the server. Be careful to ensure that both the MAX5 and the server to which it is attached are

plugged into the same common power sources.

When two x3850 X5 servers are connected as a single complex, the loss of total ac power on

either node will power both nodes down. The primary node will not power on unless ac power

is supplied to the secondary node or the QPI cables are completely disconnected from the

primary node.

You want to ensure that half of the power supplies of both units are plugged into one utility

power source and that the remaining half are plugged into a separate utility power source.