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 does vmstat stand for?
virtual memory statistics
Resolution. 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.
What information can vmstat provide?
vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity. The first report produced gives averages since the last reboot. Additional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.
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 The shared memory column should be ignored; it is obsolete.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.
Why we use 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 non nice user CPU ticks?
any cpu tick by user process which was not nice’d nice is a way to change priorities of processes http://en.wikipedia.org/wiki/Nice_(Unix) if you do not use this command to manipulate priorities you most likely end up all your user cpu ticks in the non nice section of the stats.
What is vmstat and iostat?
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.
Which vmstat command is used to show all disk statistics?
Example: The figure given below shows the table of various event counters. Disk Statics: This command is used to display all disk statistics.
What is use of vmstat and explain its output and log files?
vmstat reports information about processes, memory, paging, block IO, traps, disks and cpu activity. The first report produced gives averages since the last reboot. Additional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.
What is WA in vmstat?
The vmstat wa column is the percentage of time that the CPU was idle with pending local disk I/O and NFS-mounted disks. If there is at least one outstanding I/O to a disk when wait is running, the time is classified as waiting for I/O.
What is steal in sar command?
Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor. As such, it only happens in virtualized environments like AWS, GCP, Azure, vSphere, and Xen. To see the steal time in Linux, run top on the command line and look for %st.