Cisco Systems UCUCSEZC220M3S Installing Multiple PCIe Cards and Resolving Limited Resources, 3-36

Chapter 3 Maintaining the Server

Installing or Replacing Server Components

Installing Multiple PCIe Cards and Resolving Limited Resources

When a large number of PCIe add-on cards are installed in the server, the system may run out of the following resources required for PCIe devices:

•Option ROM memory space

•16-bit I/O space

The topics in this section provide guidelines for resolving the issues related to these limited resources.

•Resolving Insufficient Memory Space to Execute Option ROMs, page 3-36

•Resolving Insufficient 16-Bit I/O Space, page 3-37

Resolving Insufficient Memory Space to Execute Option ROMs

The system has very limited memory to execute PCIe legacy option ROMs, so when a large number of PCIe add-on cards are installed in the server, the system BIOS might not able to execute all of the option ROMs. The system BIOS loads and executes the option ROMs in the order that the PCIe cards are enumerated (Slot 1, Slot 2, Slot 3, etc.).

If the system BIOS does not have sufficient memory space to load any PCIe option ROM, it skips loading that option ROM, reports a system event log (SEL) event to the CIMC controller and reports the following error in the Error Manager page of the BIOS Setup utility:

ERROR CODE	SEVERITY	INSTANCE	DESCRIPTION
146	Major	N/A	PCI out	of resources error.
			Major severity		requires user
			intervention but does not
			prevent	system	boot.

To resolve this issue, disable the Option ROMs that are not needed for system booting. The BIOS Setup Utility provides the setup options to enable or disable the Option ROMs at the PCIe slot level for the PCIe expansion slots and at the port level for the onboard NICs. These options can be found in the BIOS Setup Utility Advanced → PCI Configuration page.

•Guidelines for RAID controller booting:

If the server is configured to boot primarily from RAID storage, make sure that the option ROMs for the slots where your RAID controllers installed are enabled in the BIOS, depending on your RAID controller configuration.

If the RAID controller does not appear in the system boot order even with the option ROMs for those slots are enabled, the RAID controller option ROM might not have sufficient memory space to execute. In that case, disable other option ROMs that are not needed for the system configuration to free up some memory space for the RAID controller option ROM.

See also Factory-Default Option ROM Settings, page C-4.

•Guidelines for onboard NIC PXE booting:

If the system is configured to primarily perform PXE boot from onboard NICs, make sure that the option ROMs for the onboard NICs to be booted from are enabled in the BIOS Setup Utility. Disable other option ROMs that are not needed to create sufficient memory space for the onboard NICs.

	Cisco UCS C220 Server Installation and Service Guide
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