Red Hat Enterprise Linux 5 Administration Unleashed

418CHAPTER 20Monitoring System ResourcesPlease wait while we collect information about your system.This process may take a while to complete....No changes will be made to your system during this process.NOTE: You can safely ignore a failed message. This only means a filewe were checking for did not exist.If your system hangs while gathering rpm information, please abortthe script with CTRL-C and run it again after adding -norpm to thesysreport command linePress ENTER to continue, or CTRL-C to quit.Press Enter to start generating the report. As information is gathered, you can see theprogress. If you see a failed message in the output, don’t worry. It just means that the informationcan not be gathered because the file doesn’t exist or you aren’t using that particularservice. As you can see from the output, sysreport gathers information about everythingincluding the kernel version, kernel modules, log files, and network configuration.After sysreport finishes, you will be prompted to enter a case number if you have one fromRed Hat Customer Service. After entering one and pressing Enter, a message will appeartelling you the filename of the report in the format /root/-..tar.bz2. To view the contents of the report, execute the command tar xjvf, where is the name of the file generated. This command creates thesubdirectory with the same filename as the archive file but without the .tar.bz2 extension.This subdirectory contains all the information gathered by sysreport.Locating Log FilesIt is extremely important to keep a watch on the system’s log files. If you are familiar withthem, it is much easier to spot a change should a problem arise or should you think yoursystem has been compromised. Log files are also useful when configuring a new device orkernel module. Error messages are written to log files and can be used to troubleshoot.You must be root to read most log files.As the system boots, it writes to the log file /var/log/dmesg. This file contains informationabout the machine as it boots such as the kernel version, options passed to the bootloader, the type of processor detected, hard drive partitions found, and which partitionsare mounted.The default system log file is /var/log/messages. It contains information such as when auser logs in, when a USB device is inserted, and when a removable device is mounted.Additional log files are located in the /var/log/ directory, with some services having theirown subdirectory such as /var/log/cups/ for the printing subsystem. Some log files arerotating log files—meaning that only a certain number are kept on the disk to conservedisk space. If all logs were kept forever, they would eventually consume the entire disk.