2 Performance and Monitoring Command Reference

This table provides information about various performance and monitoring commands.

Action Command Description
Monitor memory usage and fix fragmented memory. adaptivemmd Adaptive Memory Management Daemon is a user space service that monitors and automatically fixes memory fragmentation on an Oracle Linux system running the Unbreakable Enterprise Kernel (UEK).
Debug read and write operations on block volumes. blktrace If the blktrace package is installed, it can be used to diagnose and troubleshoot problems with block devices.
Review x86_64 CPU power statistics. cpupower If the kernel-tools package is installed, displays CPU power statistics and sets CPU power states.
Review file system disk space usage. df -h Displays a list of system mounted volumes including their capacity and how much of that capacity is free or in use.
Review messages in the kernel ring buffer. sudo dmesg Displays device error messages and records of USB device connections after system boot.
Review used and available memory. free Displays the total physical and swap memory available and where that memory is allocated.
Open a graphical user interface for reviewing performance data and ending processes. gnome-system-monitor Starts the graphical system monitor for displaying running processes, memory usage, and mounted file systems.
Monitor block volume I/O activity. iostat If the sysstat package is installed, displays the amount of time that mounted block volumes are active and their average data transfer rates.
Monitor processes creating block volume I/O activity. sudo iotop If the iotop package is installed, displays a list of processes that are performing read and write operations on mounted block volumes.
Review statistics for each networking device. ip -s link Displays network statistics and errors for all network devices, including packets transmitted (TX) and received (RX). The dropped and overrun fields provide an indicator of network interface saturation.
Review CPU statistics. sudo mpstat If the sysstat package is installed, displays detailed usage statistics for each CPU.
Monitor block volume I/O activity for NFS mounts. nfsiostat If the nfs-utils package is installed, displays activity statistics for NFS mounts.
Review system activity information. sar If the sysstat package is installed, different options for the sar command can be used to display CPU, memory, and file system usage statistics.
Review statistics for each networking protocol. ss -s Displays network statistics for protocols such as TCP and UDP.
Review running system and user space processes. top Displays navigable list of processes and their system resource usage.
Review real time reports on x86_64 CPU resource usage. turbostat If the kernel-tools package is installed, displays detailed CPU statistics such as processor frequency, temperature, power usage, and so on.
Review how long the system has been running. uptime Displays a single line summary of how long the system has been running and load average statistics.
Review memory usage statistics. vmstat Displays detailed virtual memory statistics.

Monitoring commands that generate a single output can be configured to run on a timed interval for monitoring purposes by using the watch command. For example, to run the mpstat command every second until it's stopped, run the following command: 

sudo watch -n 1 mpstat

This generates a single-line output that changes information every second, for example:

hh:mm:ss  CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal  %guest  %gnice   %idle
hh:mm:ss  all    1.44    0.02    0.80    0.01    0.07    0.05    0.06    0.00    0.00   97.56

To exit the watch command, press the Ctrl + C keys in combination.

Many of the monitoring commands listed also provide this functionality without needing to use the watch command. For example, to run the mpstat command every second until it's stopped, run the following command: 

sudo mpstat 1

To verify whether a command provides this option, check its respective manual page.

Note:

If Oracle Linux is running in a slim container, or on an Oracle Cloud Infrastructure instance, install the procps-ng package to gain access to monitoring tools such as free, top, and vmstat.