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IBM System x3950 M2 and x3850 M2 Technical Introduction
The system scans PCI Express slots to assign system resources. The system attempts to
start the first device found, with the search order as follows:
a. DVD-ROM.
b. Optional USB diskette drive.
c. Integrated SAS devices.
d. Internal PCI slots (in the order 1, 2, 3, 4, 5, 6, 7).
e. Integrated dual Gigabit Ethernet controller.
f. For multinode complexes, the ordering continues as 8,9,10,11,12,13, 14 and so forth.
During boot, you may get POST error 1801 if there are more than three different types of
SAS controllers installed, due to limited PCI ROM address space. 1801 errors are caused
by an over-subscription of the 128 KB PCI ROM resource space.
Consider the following when reviewing possible sources of 1801 errors:
– The onboard SAS controller counts as one, except if a ServeRAID MR10k is installed.
– The ServeRAID MR10k and ServeRAID MR10M are considered the same for this
purpose and therefore, only count as one.
Broadcom dual Gigabit Ethernet controller
The x3850 M2 and x3950 M2 offer a dual Gigabit Ethernet controller integrated standard in
the system. The x3850 M2 and x3950 M2 include one dual-port Broadcom BCM5709C
10/100/1000 BASE-T MAC (Media Access Controller) on the PCI Express x4 bus. The
BCM5709C has the following features:
Supports full and half-duplex performance at all speeds (10/100/1000 Mbps,
auto-negotiated)
Provides two IEEE 802.3 Ethernet MAC addresses
Includes integrated on-chip memory for buffering data transmissions to ensure the highest
network performance
Includes dual onboard DMA engines to maximize bus throughput and minimize CPU
overhead
Supports IPMI for system management
The Broadcom controller also includes software support for failover, layer-3 load balancing,
and comprehensive diagnostics.
Category 5 or better Ethernet cabling is required with RJ-45 connectors. If you plan to
implement a Gigabit Ethernet connection, ensure that your network infrastructure is capable
of the necessary throughput to match the server’s I/O capacity.
Redundancy
The x3850 M2 and x3950 M2 have the following redundancy features to maintain high
availability:
There are six hot-swap, multi-speed fans. These fans provide cooling redundancy and
enable individual fan replacement without powering down the server.
Each of the three groups of two fans is redundant. In the event of a fan failure, the other
fans will speed up to continue to provide adequate cooling until the fan can be