linux vmstat - ghdrako/doc_snipets GitHub Wiki

vmstat - tool for monitoring system performance and analyzing resource usage. When executed, the vmstat command provides a detailed report on various system statistics, including CPU usage, memory usage, virtual memory, disk I/O, and system processes.

  • procs: This displays information about processes and process states.
    • The r column represents the number of processes in the running state, and
    • the b column indicates the number of processes in the uninterruptible sleep or blocked state.
  • memory: This provides details about memory usage.
    • The swpd column shows the amount of virtual memory used (in KB) that has been swapped to the disk.
    • The free column displays the amount of free memory (in KB) available for processes.
    • The buff column shows the amount of memory (in KB) used as buffer cache by the kernel.
    • The cache column displays the amount of memory (in KB) used as page cache by the kernel.
  • swap: This displays information about swap space usage.
    • The si column represents the amount of memory (in KB) swapped in from disk per second, and
    • the so column represents the amount of memory (in KB) swapped out to disk per second.
  • io: This provides information about I/O operations.
    • The bi column shows the number of blocks received from a block device (such as a hard disk) per second, and
    • the bo column shows the number of blocks sent to a block device per second.
  • system: This section displays system-related statistics.
    • The in column represents the number of interrupts per second, and
    • the cs column represents the number of context switches per second.
  • cpu: This section provides CPU utilization statistics.
    • The us column represents the percentage of CPU time spent in user-level processes.
    • The sy column represents the percentage of CPU time spent in system-level processes.
    • The id column represents the percentage of idle CPU time.
    • The wa column represents the percentage of CPU time spent waiting for I/O operations.
    • The st column represents the percentage of CPU time stolen from a virtual machine (VM).