Top (Topas), Vmstat,iostat is displayed under Linux and AIX operating systems

Top (Topas), Vmstat,iostat is displayed under Linux and AIX operating systemsCategory: Linux basics 2013-08-09 17:26 1093 people read reviews (0) favorite reports

Detailed list of commands commonly used parameters, in their own virtual machine, the requirements of each row is not listed information explained clearly, there are different operating system platform under the different commands. For example, Linux and Aix under the top command output of the different.

Top (Linux system)

The top command is a common performance analysis tool under Linux that shows the resource usage of individual processes in the system in real time, similar to the Task Manager for Windows.

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Up: System Run time

Load average: The system load, which is the average length of the task queue.

Zomibie: Zombie process. Zombie Process Consuming threads

CPU (s): 1.7% US User space consumes Cpu percentage 1.5% SY core space CPU percent occupied 0.0% CPU Percentage of processes that have changed priority within NI user process space 96.8% ID Idle CPU percent 0.0% wa Wait for the input output CPU time percentage 0.0% Hi 0.0% si Mem Physical Memory Buffer: The amount of cache used as the kernel Swap swap Area Cached: Total buffer swap area   PR-Priority a Ni:nice value that represents a high priority, and a positive number represents a low priority. The total amount of virtual memory used by the VIRT process, in kilobytes. Virt=swap+res The size, in kilobytes, of the physical memory used by the RES process and not swapped out. Res=code+data SHR Shared memory size, in kilobytes total CPU time used by the time+ process Command name/command line   the others are better understood, so they don't have to be listed.
Topas (under AIX system)

The Topas command reports important statistics about the activity in the local system, the true memory size, and the number of write operating system calls.

Vmstat command

The Vmstat command reports statistical information about kernel threads, virtual memory, disks, traps, and CPU activity.

These system-wide statistics (all processors) calculate the average as a percentage, or calculate its sum.

R: The number of kernel threads placed in the running queue.

B: The number of kernel threads placed in the wait queue (waiting for resources, waiting for input/output).

Swpd

Free: Idle memory

BUFF:CPU Kernel Cache

Cache: Switch Caching

In: Device interrupt

SY: System call.

CS: Kernel thread context switch.

US: Number of users.

SY: System time.

Id:cpu percent usage.

Wa:cpu idle percentage, during which the system has outstanding disk/NFS I/O.

As for the AIX system, Vmstat is also used to view memory information.

The system you see with Vmstat has very little left, but in fact your app doesn't use that much memory, it just divides it into your app, and it's best to use Topas to see how much memory your app uses.
Iostat

There is no such command in the Linux system

In Aix systems

Reports input/output statistics for the central Processing Unit (CPU) statistics and the entire system, adapter, TTY device, disk, and CD-ROM.

Tin

Shows the total number of characters read by the system for all TTY.

Tout

Shows the total number of characters written by the system for all TTY.

% User

Shows the percentage of CPU usage that is generated at User level (application) execution.

% SYS

Shows the percentage of CPU usage that is generated at the system level (kernel) execution.

% Idle

Shows the percentage of time when the CPU is idle and the system does not have outstanding disk I/O requests.

% iowait

Shows the percentage of time that the system has outstanding disk I/O requests during the CPU idle period.

Top (Topas), Vmstat,iostat is displayed under Linux and AIX operating systems