What is Bi and Bo in vmstat?
IO bi: Blocks received from a block device (blocks/s). bo: Blocks sent to a block device (blocks/s). System in: The number of interrupts per second, including the clock. cs: The number of context switches per second.
What is difference between Iostat and vmstat?
vmstat command (also known as virtual memory statistic tool) shows information about processes, memory, disk, and CPU activity in Linux, whereas the iostat command is used to monitor CPU utilization, system input/output statistics for all the disks and partitions.
What is the vmstat command in Linux?
The vmstat command (short for virtual memory statistics) is a built-in monitoring utility in Linux. The command is used to obtain information about memory, system processes, paging, interrupts, block I/O, disk, and CPU scheduling. Users can observe system activity virtually in real-time by specifying a sampling period.
What is vmstat?
The vmstat command reports statistics about kernel threads in the run and wait queue, memory, paging, disks, interrupts, system calls, context switches, and CPU activity. The reported CPU activity is a percentage breakdown of user mode, system mode, idle time, and waits for disk I/O.
What is the use of vmstat in tuning?
Use vmstat to determine real and logical resource utilization. It samples kernel tables and counters and then normalizes the results and presents them in an appropriate format. By default, vmstat sends its report to standard out, but it can be run with the output redirected.
How do I exit vmstat?
The count value tells vmstat how many updates to perform before it exits and returns you to the command prompt. If you do not provide a count value, vmstat will run until it is stopped by Ctrl+C.
What is vmstat in Linux?
Linux Performance Measurements using vmstat. vmstat (virtual memory statistics) is a valuable monitoring utility, which also provides information about block IO and CPU activity in addition to memory.
Why does vmstat report 512 bytes as a block size?
These reports are intended to help identify system bottlenecks. Linux vmstat does not count itself as a running process. All linux blocks are currently 1024 bytes. Old kernels may report blocks as 512 bytes, 2048 bytes, or 4096 bytes. Since procps 3.1.9, vmstat lets you choose units (k, K, m, M).
How do I update The vmstat statistics?
To have the statistics updated every 10 seconds with the memory and swap statistics displayed in megabytes, use the following command: vmstat 10 -S M. The memory and swap statistics are now shown in megabytes. Note that the -S option does not affect the IO block statistics. These are always displayed in blocks. Active and Inactive Memory
What permissions does vmstat require?
vmstat does not require special permissions. These reports are intended to help identify system bottlenecks. Linux vmstat does not count itself as a running process. All linux blocks are currently 1024 bytes. Old kernels may report blocks as 512 bytes, 2048 bytes, or 4096 bytes.