Linux Commands To View Page Faults Statistics

There are several Linux commands that you can use to view page fault statistics, which are counts of the number of times that the system has to access the virtual memory or swap space to retrieve a page of data. Page faults can occur when a process attempts to access a page of memory that is not currently in physical memory (RAM), and the system must retrieve the page from the virtual memory or swap space on the hard drive. High levels of page faults can indicate that the system is running low on available memory, or that a process is using memory inefficiently.

Here are four Linux commands that you can use to view page fault statistics:

vmstat:

The vmstat command is a utility that displays statistics about the virtual memory, processes, block I/O, and other aspects of the system. To view page fault statistics with vmstat, you can use the following command:

$ vmstat -s

This will display a list of various statistics, including the number of page faults. The page faults are listed as pgfault, which is the number of major page faults (i.e., page faults that required I/O to retrieve the page), and pgmajfault, which is the number of minor page faults (i.e., page faults that did not require I/O).

cat /proc/vmstat:

The /proc/vmstat file is a virtual file that contains a variety of statistics about the virtual memory and paging activity on the system. To view the page fault statistics from /proc/vmstat, you can use the cat command to display the contents of the file:

$ cat /proc/vmstat

This will display a list of the statistics in the /proc/vmstat file, including the number of page faults (pgfault and pgmajfault).

sar -B:

The sar (System Activity Report) is a command-line utility that is used to monitor and report various aspects of system activity in a Linux system. It is part of the sysstat package, which is a collection of utilities that provide information about system performance.

sar allows you to collect and view data about various aspects of system activity, such as CPU utilization, memory usage, disk I/O, network traffic, and more. You can use sar to monitor the performance of your system in real-time, or you can use it to collect data over a period of time and view a summary of the collected data.

To use sar, you can simply type sar followed by the options and arguments that specify the type of data you want to view. For example, to view the CPU utilization for the current day, you can use the following command:

sar -u

You can also use sar to view data for a specific time period. For example, to view the CPU utilization for the past 24 hours, you can use the following command:

sar -u -f /var/log/sa/saXX

Where XX is the current day of the month.

There are many options and arguments that you can use with sar, so you can view a wide variety of system activity data. To learn more about sar and see a full list of options and arguments, you can type man sar at the command prompt.

perf:

The perf command is a utility that allows you to collect and view performance data on a Linux system. To view page fault statistics with perf, use the following command:

perf record -e page-faults -a sleep 10
perf report

This will record page fault data for a period of 10 seconds, and then display a report of the collected data.