Appendix B. Tools and tips for troubleshooting and bug reporting

Procedure

1. Select the Install Red Hat Enterprise Linux option from the boot menu.
2. Press the Tab key on BIOS-based systems or the e key on UEFI-based systems to edit the selected boot options.

3. Append inst.debug to the options. For example:

   vmlinuz ... inst.debug

4. Press the Enter key on your keyboard. The system stores the pre-installation log files in the /tmp/pre-anaconda-logs/ directory before the installation program starts.
5. To access the log files, switch to the console.

6. Change to the /tmp/pre-anaconda-logs/ directory:

   # cd /tmp/pre-anaconda-logs/

Procedure

1. Press Ctrl + Alt + F2 to access a shell prompt on the system you are installing.

2. Connect a USB flash drive to the system and run the dmesg command:

   # dmesg

   A log detailing all recent events is displayed. At the end of this log, a set of messages is displayed. For example:

   [ 170.171135] sd 5:0:0:0: [sdb] Attached SCSI removable disk

3. Note the name of the connected device. In the above example, it is sdb.

4. Navigate to the /mnt directory and create a new directory that serves as the mount target for the USB drive. This example uses the name usb:

   # mkdir usb

5. Mount the USB flash drive onto the newly created directory. In most cases, you do not want to mount the whole drive, but a partition on it. Do not use the name sdb, use the name of the partition you want to write the log files to. In this example, the name sdb1 is used:

   # mount /dev/sdb1 /mnt/usb

6. Verify that you mounted the correct device and partition by accessing it and listing its contents:

   # cd /mnt/usb

   # ls

7. Copy the log files to the mounted device.

   # cp /tmp/*log /mnt/usb

8. Unmount the USB flash drive. If you receive an error message that the target is busy, change your working directory to outside the mount (for example, /).

   # umount /mnt/usb

Procedure

1. Press Ctrl + Alt + F2 to access a shell prompt on the system you are installing.

2. Switch to the /tmp directory where the log files are located:

   # cd /tmp

3. Copy the log files onto another system on the network using the scp command:

   # scp *log user@address:path

   1. Replace user with a valid user name on the target system, address with the target system’s address or host name, and path with the path to the directory where you want to save the log files. For example, if you want to log in as john on a system with an IP address of 192.168.0.122 and place the log files into the /home/john/logs/ directory on that system, the command is as follows:

      # scp *log john@192.168.0.122:/home/john/logs/

      When connecting to the target system for the first time, the SSH client asks you to confirm that the fingerprint of the remote system is correct and that you want to continue:

      The authenticity of host '192.168.0.122 (192.168.0.122)' can't be established.
      ECDSA key fingerprint is a4:60:76:eb:b2:d0:aa:23:af:3d:59:5c:de:bb:c4:42.
      Are you sure you want to continue connecting (yes/no)?

   2. Type yes and press Enter to continue. Provide a valid password when prompted. The files are transferred to the specified directory on the target system.

Procedure

1. From the Red Hat Enterprise Linux boot menu, select Troubleshooting > Run a memory test. The Memtest86 application window is displayed and testing begins immediately. By default, Memtest86 performs ten tests in every pass. After the first pass is complete, a message is displayed in the lower part of the window informing you of the current status. Another pass starts automatically.

   If Memtest86+ detects an error, the error is displayed in the central pane of the window and is highlighted in red. The message includes detailed information such as which test detected a problem, the memory location that is failing, and others. In most cases, a single successful pass of all 10 tests is sufficient to verify that your RAM is in good condition. In rare circumstances, however, errors that went undetected during the first pass might appear on subsequent passes. To perform a thorough test on important systems, run the tests overnight or for a few days to complete multiple passes.

   Note

   The amount of time it takes to complete a single full pass of Memtest86+ varies depending on your system’s configuration, notably the RAM size and speed. For example, on a system with 2 GiB of DDR2 memory at 667 MHz, a single pass takes 20 minutes to complete.

2. Optional: Follow the on-screen instructions to access the Configuration window and specify a different configuration.
3. To halt the tests and reboot your computer, press the Esc key at any time.