Cheatsheet & Examples: vmstat

Cheatsheet & Examples: vmstat

vmstat (Virtual Memory Statistics) provides a real-time view of system performance by reporting statistics about processes, memory, paging, I/O, CPU activity, and other aspects of system performance. It's a useful tool for identifying performance bottlenecks.

Displaying System Performance Snapshot

Example Usage: vmstat 1

What it does: Displays a single snapshot of system statistics with a 1-second interval.

Command-line Arguments Explained:

1: The interval in seconds between each update. In this case, it refreshes the output every second.

Continuously Monitoring System Performance

Example Usage: vmstat 5 3

What it does: Displays system statistics repeatedly, updating every 5 seconds, and showing 3 updates total.

Command-line Arguments Explained:

5: The interval in seconds between each update.
3: The number of updates to display. If omitted, vmstat will run indefinitely.

Displaying Specific Statistics with -a option

Example Usage: vmstat -a 5 2

What it does: Displays more detailed memory statistics, including active and inactive memory. This can be helpful for understanding memory usage patterns. It refreshes the output every 5 seconds and shows 2 updates total.

Command-line Arguments Explained:

-a: Displays active and inactive memory statistics.
5: The interval in seconds between each update.
2: The number of updates to display.

Displaying Disk Statistics

Example Usage: vmstat -d 5 2

What it does: Displays disk statistics, offering insights into disk I/O performance. It refreshes the output every 5 seconds and shows 2 updates total.

Command-line Arguments Explained:

-d: Displays disk statistics.
5: The interval in seconds between each update.
2: The number of updates to display.

Displaying Disk Statistics and Processes information

Example Usage: vmstat -d -p 5 2

What it does: Displays both disk statistics and process information, offering a more comprehensive view of system resource usage, focusing on disk I/O, it refreshes the output every 5 seconds and shows 2 updates total.

Command-line Arguments Explained:

-d: Displays disk statistics.
-p: Displays process information
5: The interval in seconds between each update.
2: The number of updates to display.

Displaying Memory Statistics and Processes information

Example Usage: vmstat -m -p 5 2

What it does: Displays both memory statistics and process information, offering a more comprehensive view of system resource usage, focusing on memory and process state, it refreshes the output every 5 seconds and shows 2 updates total.

Command-line Arguments Explained:

-m: Displays memory statistics.
-p: Displays process information
5: The interval in seconds between each update.
2: The number of updates to display.

Displaying Slabinfo Information

Example Usage: vmstat -S 5 2

What it does: Displays slabinfo, providing insights into the kernel's memory allocation efficiency. It refreshes the output every 5 seconds and shows 2 updates total.

Command-line Arguments Explained:

-S: Displays slabinfo statistics.
5: The interval in seconds between each update.
2: The number of updates to display.