Hardware Issues

Diagnosing SAS Data Path Failures on Servers Using MegaRAID Disk Controllers

Important Operating Note

On Oracle x86 servers using MegaRAID disk controllers, Serial Attached SCSI (SAS) data path errors can occur. To triage and isolate a data path problem on the SAS disk controller, disk backplane (DBP), SAS cable, SAS expander, or hard disk drive (HDD), gather and review the events in the disk controller event log. Classify and analyze all failure events reported by the disk controller based on the server SAS topology.

To classify a MegaRAID disk controller event:

Gather and parse the MegaRAID disk controller event logs either by running the automated sundiag utility or manually using the or StorCLI command.
- For Oracle Exadata Database Machine database or storage cell servers, run the sundiag utility.
- For Oracle Server X7-2L, use the StorCLI command.

For example, manually gather and parse the controller event log by using the StorCLI command. At the root prompt, type:

root# ./storcli64/c0 show events file=event.log
Controller=0
Status=Success

Note:

Use the existing name of the event log as the name for the disk controller event log. This produces a MegaRAID controller event log with the given file name event.log.

To show drive and slot errors separately, at the root prompt, type:

root# /opt/MegaRAID/storcli/storcli64 /c0 /eall /sall show errorcounters
Controller=0
Status=Success
Description=Show Drive/Cable Error Counters Succeeded.

Error Counters:

Drive	Error Counter for Drive Error	Error Counter for Slot
/c0/e8/s0	0	0
/c0/e8/s1	0	0
/c0/e8/s2	0	0
/c0/e8/s3	0	0
/c0/e8/s4	0	0
/c0/e8/s5	0	0
/c0/e8/s12	0	0
/c0/e8/s13	0	0

These error counters reflect drive or slot errors separately.

The following SCSI sense key errors found in the event log in SAS data path failures indicate a SAS data path fault:

B/4B/05 :SERIOUS: DATA OFFSET ERROR
B/4B/03 :SERIOUS: ACK/NAK TIMEOUT
B/47/01 :SERIOUS: DATA PHASE CRC ERROR DETECTED
B/4B/00 :SERIOUS: DATA PHASE ERROR

A communication fault between the disk and the host bus adapter causes these errors. The presence of these errors, even on a single disk, means there is a data path issue. The RAID controller, SAS cables, SAS expander, or disk backplane might be causing the interruption to the communication in the path between the RAID controller and the disks.

Oracle Service personnel can find more information about the diagnosis and triage of hard disk and SAS data path failures on x86 servers at the My Oracle Support web site: https://support.oracle.com . Refer to the Knowledge Article Doc ID 2161195.1. If there are multiple, simultaneous disk problems on an Exadata server, Oracle Service personnel can refer to Knowledge Article Doc ID 1370640.1.

Parent topic: Hardware Issues

Failure of a Single Server Fan Module Might Impact Performance

Important Operating Note

If a single server fan module fails and the server's operating temperature rises above 30 degrees C (86 degrees F), the performance of the server's processors might be reduced.

Parent topic: Hardware Issues

Remove and Replace a Fan Module Within 20 Seconds

Important Operating Note

When removing and replacing a server fan module, you must complete the entire removal and replacement procedure within 20 seconds in order to maintain adequate cooling within the system. In anticipation of this time limit, prior to starting the replacement procedure, obtain the replacement fan module and verify that the new fan module is ready for installation. Remove and replace only one fan module at a time.

Fan modules are hot-swappable components, with N+1 fan redundancy. Each fan module contains two fans, with one fan motor per fan. The two fan motors provide separate tachometer signals so that the fan module reports two tachometer signals to Oracle ILOM. Even if only one fan motor is faulted within the fan module, the Oracle ILOM service processor detects that two fan motors have failed to spin while the fan module is removed. If the fan module is not replaced within 20 seconds of removal, Oracle ILOM will take the protective action to shut down the system to prevent thermal damage to the system. This is expected behavior.

Parent topic: Hardware Issues

Lockstep Memory (Channel) Mode Is Not Supported

Important Operating Note

Your Oracle Server X7-2L does not support lockstep memory mode, which is also known as double device data correction, or Extended ECC.

Parent topic: Hardware Issues

MAC Address Mapping to Ethernet Ports

Important Operating Note

A system serial label that displays the MAC ID (and the associated barcode) for the server is attached to the top, front-left side of the Oracle Server X7-2L server disk cage bezel.

This MAC ID (and barcode) corresponds to a hexadecimal (base 16) MAC address for a sequence of six consecutive MAC addresses. These six MAC addresses correspond to the server's network ports as shown in the following table.

Base MAC Address	Corresponding Ethernet Port
“base” + 0	NET 0
“base” + 1	Unassigned
“base” + 2	Unassigned
“base” + 3	Unassigned
“base” + 4	SP (NET MGT)
“base” + 5	Used only when Network Controller-Sideband Interface (NC-SI) sideband management is configured.

Parent topic: Hardware Issues

Do Not Mix Single-Rank and Dual-Rank DIMMs

Important Operating Note

Mixing of single-rank and dual-rank DIMMs in the Oracle Server X7-2L is not supported.

Parent topic: Hardware Issues

Oracle Dual Port 25 Gb Ethernet Adapter Can Experience a Fault During System Reset

Bug ID: 26259122

Issue: The Oracle Dual Port 25 Gb Ethernet Adapter can experience a completion timeout fault during a system warm reset operation. The fault is logged by Oracle ILOM.

Affected Hardware: Oracle Dual Port 25 Gb Ethernet Adapter

Workaround: This issue has no functional impact on normal system behavior and can be ignored.

Parent topic: Hardware Issues