What should I look for in vmstat?
What to Look for in vmstat
- r (runqueue) The runqueue value shows the number of tasks executing and waiting for CPU resources.
- pi (page in) A page-in operation occurs when the server is experiencing a shortage of RAM memory.
- us (user CPU) This is the amount of CPU that is servicing user tasks.
What is vmstat output?
vmstat (virtual memory statistics) is a valuable monitoring utility, which also provides information about block IO and CPU activity in addition to memory. vmstat Basics. vmstat provides a number of values and will typically be called using two numerical parameters.
Why we use vmstat 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 run queue in vmstat?
The vmstat UNIX or Linux command can also be used to determine the number of processes that are queued to run or waiting to run. These appear in the ‘r’ column. There are two models for Run queues: one that assigns a Run Queue to each physical processor, and the other has only one Run Queue in the system.
What is free in vmstat?
From the manpages: free, vmstat. free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel. The shared memory column should be ignored; it is obsolete. vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.
How much memory is my Mac using?
To check RAM usage on your Mac, go to Activity Monitor (Applications > Utilities). In the Memory tab, you will see all the active processes that are using your Mac’s RAM. At the end of the window, there is a Memory Used graph, which indicates how much application memory is used.
What is difference between sar and vmstat in Linux?
I managed to figure out the difference of swap data: for sar uses 512-bytes bloks, while vmstat uses kbytes. that makes the numbers somewhat alike. but when it comes to freememory, things are a little bit more difficult.