How to check linux restart logs? (2023)

How to check linux restart logs?

For CentOS/RHEL systems, you'll find the logs at /var/log/messages while for Ubuntu/Debian systems, its logged at /var/log/syslog . You can simply use the tail command or your favorite text editor to filter out or find specific data.

Check your /etc/syslog. conf or /etc/rsyslog. conf or equivalent to make sure logs are going there. You'll probably need root privileges to read the log files.

Use who command to find last system reboot time/date

The pseudo user reboot logs in each time the system is rebooted. Thus last reboot command will show a log of all reboots since the log file was created.

This is such a crucial folder on your Linux systems. Open up a terminal window and issue the command cd /var/log. Now issue the command ls and you will see the logs housed within this directory (Figure 1).

Linux System Logs

Linux has a special directory for storing logs called /var/log . This directory contains logs from the OS itself, services, and various applications running on the system.

Read dmesg Log File

Each time the system boots up, the messages from the kernel ring buffer are stored in the /var/log/dmesg file. The dmesg command shows the log file contents. If you have issues using the dmesg command, open the log file in a text editor to view the contents.

The tail command, as the name implies, print the last N number of data of the given input. By default it prints the last 10 lines of the specified files. If more than one file name is provided then data from each file is precedes by its file name.

The best way to check the last reboot time in Linux is using the last reboot command. Open the terminal and type last reboot. It will show all reboots since the log file was created. To list the last reboot time, run last reboot| head -2.

What is proc uptime?

Using /proc/uptime

Shows how long the system has been on since it was last restarted: $ cat /proc/uptime 350735.47 234388.90. The first number is the total number of seconds the system has been up. The second number is how much of that time the machine has spent idle, in seconds.

The last command displays information about the last logged-in users. It's pretty convenient and handy when we need to track login activities or investigate a possible security breach. The last command will, by default, take the system log file /var/log/wtmp as the data source to generate reports.

Click on the Syslog tab to view system logs. You can search for a specific log by using ctrl+F control and then enter the keyword. When a new log event is generated, it is automatically added to the list of logs and you can see it in bolded form.

You can read a LOG file with any text editor, like Windows Notepad. You might be able to open one in your web browser, too. Just drag it directly into the browser window, or use the Ctrl+O keyboard shortcut to open a dialog box to browse for the file.

One of the simplest ways to analyze logs is by performing plain text searches using grep. grep is a command line tool that can search for matching text in a file, or in output from other commands. It's included by default in most Linux distributions and is also available for Windows and Mac.

Where is the syslog in Linux?

syslog() generates a log message, which will be distributed by syslogd. The file to configure syslogd is /etc/syslog. conf. This file will tell your where the messages are logged.

nslookup is a command-line administrative tool for testing and troubleshooting DNS servers (Domain Name Server). It is used to query specific DNS resource records (RR) as well.

Uptime is a command that returns information about how long your system has been running together with the current time, number of users with running sessions, and the system load averages for the past 1, 5, and 15 minutes. It can also filter the information displayed at once depending on your specified options.

This is where the Linux w command can help. The w command is a built-in tool that allows administrators to view information about users that are currently logged in. This includes their username, where they are logged in from, and what they are currently doing.

dmesg command also called as “driver message” or “display message” is used to examine the kernel ring buffer and print the message buffer of kernel. The output of this command contains the messages produced by the device drivers.

Clear dmesg Buffer Logs

Still you can view logs stored in '/var/log/dmesg' files. If you connect any device will generate dmesg output.

You can use journalctl to display only messages of a specified priority or above by using the -p option. This allows you to filter out lower priority messages. For instance, to show only entries logged at the error level or above, you can type: journalctl -p err -b.

Press Shift-F. This will take you to the end of the file, and continuously display new contents. In other words, it behaves just like tail -f. To scroll backwards, you must first exit the follow mode by pressing Control-c.

wc (short for word count) is a command in Unix, Plan 9, Inferno, and Unix-like operating systems. The program reads either standard input or a list of computer files and generates one or more of the following statistics: newline count, word count, and byte count.

How can I tell the last time a command prompt was rebooted?

Linux system restart

To reboot the Linux system from a terminal session, sign in or “su”/”sudo” to the “root” account. Then type “ sudo reboot ” to reboot the box. Wait for some time and the Linux server will reboot itself.

The top (table of processes) command shows a real-time view of running processes in Linux and displays kernel-managed tasks. The command also provides a system information summary that shows resource utilization, including CPU and memory usage. In this tutorial, you will learn to use the top command in Linux.

To check Windows uptime with Task Manager, right-click the Windows taskbar and select Task Manager or press Ctrl–Shift–Esc. Once Task Manager is open, click on the Performance tab. Under the Performance tab, you will see a label of Up Time.

The uptime is normally displayed in days, hours, and minutes as appropriate. However, various options let you view the uptime only in days, hours, seconds, or milliseconds, as needed. The current time is the local time and is displayed in hh:mmmmmam/pm format.

Uptime is a computer industry term for the time during which a computer is operational. Downtime is the time when it isn't operational. Uptime is sometimes measured in terms of a percentile.

Updated: 05/03/2022 by Computer Hope. On the Linux, Solaris, and BSD operating systems, wtmp is a file containing a history of all logins and logouts. On Linux systems, it is located at /var/log/wtmp. Various commands access wtmp to report login statistics, including the who and lastb commands.

On Unix-like operating systems, the last command displays a list of the most recently logged in users. On Linux operating systems, the supplemental lastb command displays a list of bad (failed) logins.

You can use Event Viewer (Eventvwr. msc) to view logs that can help you to identify system problems when you are able to start the system in safe or normal mode. When you are troubleshooting, use these logs to isolate problems by application, driver, or service and to identify frequently occurring issues.

What is the event ID for shutdown?

Event ID 1074: System has been shutdown by a process/user.

This event is written when an application causes the system to restart, or when the user initiates a restart or shutdown by clicking Start or pressing CTRL+ALT+DELETE, and then clicking Shut Down.

How do I view crash logs in Linux? Linux logs can be viewed with the command cd/var/log, then by typing the command ls to see the logs stored under this directory. One of the most important logs to view is the syslog, which logs everything but auth-related messages.

A Kernel Crash Dump refers to a portion of the contents of volatile memory (RAM) that is copied to disk whenever the execution of the kernel is disrupted. The following events can cause a kernel disruption : Kernel Panic. Non Maskable Interrupts (NMI) Machine Check Exceptions (MCE)

/var/log/syslog or /var/log/messages: Shows general messages and info regarding the system. Basically a data log of all activity throughout the global system. Know that everything that happens on Redhat-based systems, like CentOS or Rhel, will go in messages.

If you are running Ubuntu and your system randomly crashes, you may be running out of memory. Low memory could be caused by opening more applications or data files than will fit in the memory you have installed. If that is the problem, do not open so much at one time or upgrade to more memory on your computer.