Ubuntu Linux Server Troubleshooting

Use dmesg to read the kernel ring buffer, inspect boot-time hardware, and grep the output in a pager for network or PCI messages; review archived logs in /var/log/kern.log.

Explore the var log directory to locate major log files such as syslog, boot log, auth log, kern log, and dpkg log, and use grep and a pager for troubleshooting.

Discover how to view hardware information in ubuntu server using lshw and ls pci, with class filters like network, multimedia, and storage, and use df -h for mounted disks.

Verify the Ubuntu Linux server has an IP address with ifconfig and confirm internet access by pinging google.com. Optionally install and use lynx to test web connectivity from the server.

Learn to use ifconfig and dhclient to release and renew a dhcp lease on Ubuntu server (eth0), with sudo root privileges and checking the interface ip address.

Learn how to configure a static IP on Ubuntu server by editing /etc/network/interfaces, using ifdown and ifup to reset the adapter, and verify connectivity with ping.

Configure wireless networking on ubuntu server by editing the interfaces file, setting wlan0 auto, choosing dhcp or static, and specifying ssid and wpa psk passphrase.

Verify the current hostname, change it in the current session with sudo hostname [new-hostname], modify /etc/hostname and /etc/hosts to make it permanent, and restart networking without reboot.

View the ARP table with arp -a, understand the address resolution protocol and how IPs map to MAC addresses, and observe ARP requests and replies enabling server communication.

Use sudo lshw -C network to view Ubuntu's network hardware, identify the network interface (for example eth0), verify its status, and bring it up with ifconfig to troubleshoot connectivity.

Test your ubuntu linux server’s download speed with wget by downloading a hosted file to view real-time transfer rates. The module previews speedtest-cli for download, upload, and ping.

Test Ubuntu server speeds with speedtest-cli and a Python script, installing Python and pip, and measure latency, download, and upload while selecting the best server.

Learn how to install software from source on Ubuntu, resolve missing dependencies like curses.h and groff, configure, compile, and test the program while interpreting error messages.

Reconfigure pending packages with dpkg --configure -a and fix broken dependencies using apt-get install -f to recover from interrupted installs.

Use sudo apt-get purge --auto-remove <package> to completely remove a debian package. Do not add an asterisk wildcard, as purge auto-remove handles related dependencies and prevents breaking the system.

Learn to use apt-get clean, autoclean, and update to manage package archives, dependencies, and read error messages for troubleshooting on Ubuntu Linux.

Diagnose motherboard issues using on-board error codes, LEDs, or a two-character display. Inspect for burn marks and bad capacitors, reset the BIOS, and check the CMOS battery and connections.

Boot Memtest86+ from GRUB on Ubuntu server (pre-installed) to test all ram outside the os, then run for about an hour (overnight if needed) to detect errors.

Test RAM on Ubuntu server on the fly without rebooting with mem tester; run as root to lock memory and note potential slowdown.

Learn to perform cpu stress testing on an Ubuntu Linux server with mprime, including downloading the correct version, extracting it, running the test, and safely ending the test.

Diagnose power supply issues by verifying the outlet, cables, power strip, and switch on the back, then test with a known-good psu to confirm the cause.

Run fsck to detect and repair filesystem errors, using sudo fsck -y to automatically fix issues on the target partition. Prepare backups and review options in the man page.

Learn to check hard drive health on Ubuntu server using smartmontools: install smartmontools, run sudo smartctl -x /dev/sdX to view smart data, and perform short or long self-tests.

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