Linux dmesg command details Function Description: displays the boot information. Syntax: dmesg [-cn] [-s] Note: The kernel stores the boot information in the ring buffer. If the information cannot be viewed during startup, you can use dmesg to view the information. The boot information is also saved in the/var/log directory and named dmesg. Parameters:-c clear the content in the ring buffer after the display is completed. The-s buffer size defines a buffer with the buffer size to be used to query the kernel ring buffer. The default size is 8196 (this size is consistent with the default syslog buffer size of the 2.0.33 and 2.1.103 kernels). If you set a ring buffer greater than the default value, then you can use this option to define a buffer to view the complete ring buffer content. -The n-level setting level is the level that records the console startup information. For example,-n 1 indicates to set this level to the lowest level, and does not display information to the console except for Kernel panic information. All levels of startup information will also be recorded in the/proc/kmsg file. Therefore, syslogd (8) can also be used to control the output of information. When the-n option is used, dmesg does not clear the content in the kernel ring buffer. When the preceding two options are used at the same time, only the last option will produce results. Example: Save the system startup information to the file: $ sudo dmesg> messages.txt prints the last message: $ sudo dmesg | tail-f