Expert Oracle Exadata - Parent Directory

CHAPTER 9 RECOVERING EXADATAprovides a wealth of diagnostic tools that can be used to verify, analyze, and report importantinformation about the configuration and health of the system. In this section, we’ll discuss some of thosetools and how to use them.Sun Diagnostics: sundiag.shInstalled on every Exadata database server and storage cell is the sundiag.sh script, located in the/opt/oracle.SupportTools directory. If for some reason you don’t find it installed on your system, youcan download it from My Oracle Support. Refer to MOS Doc ID 761868.1. This script is run from the rootaccount and collects diagnostic information needed for troubleshooting disk failures. The files it collectsare bundled in the familiar tar format and then compressed using bzip2.sundiag.sh OutputThe log files produced by sundiag.sh are named using the host name of the server, followed by adescriptive name, and postfixed with the date and time of the report. For example, running the script onour lab system produced an output file (created by the demsg command) named as follows:enkdb01_dmesg_2011_01_28_09_42.outNow, let’s take a look at the diagnostic files collected by sundiags.sh.messages: This is a copy of the /var/log/messages file from your system. Themessages file is rotated and aged out automatically by the operating system. Ifyour system has been running for a while, you will have several of these filesenumerated in ascending order from current (messages) to oldest (messages.4).This file is maintained by the syslog daemon and contains importantinformation about the health and operation of the operating system.dmesg: This file is created by the dmesg command and contains diagnostickernel-level information from the kernel ring buffer. The kernel ring buffercontains messages sent to or received from external devices connected to thesystem, such as disk drives, keyboard, video, and so on.lspci: This file contains a list of all the PCI buses on the system.lsscsi: The lsscsi file contains a list of all the SCSI drives on the system.fdisk-l: The fdisk-l file contains a listing of all disk device partitions in yoursystem.sel-list: The sel-list file contains output from the ipmitool sel elistcommand. IPMI stands for Intelligent Platform Management Interface and ispart of the ILOM (Integrated Lights Out Management) component. Theipmitool command taps into the ILOM and extracts sensor readings on all IPMIenabled devices such as memory and CPU.megacli64: The sundiags.sh script runs the MegaCli64 command with variousoptions that interrogate the MegaRAID controller for information on theconfiguration and status of your disk controller and attached disk drives. Thereis a wealth of information collected by the MegaRAID controller that can beeasily tapped into using the MegaCli64 command. For example, the following276