PT - IOSTAT MPSTAT Performance Monitoring commands

PT -  IOSTAT  MPSTAT  Performance Monitoring commands 

iostat 

• iostat cpu  performance output at every 2 seconds

iostat -c 2 

• iostat  overlall  performance output at every 2 seconds

iostat 2 

• MPSTAT performance output  at every 2 second 

mpstat 

mpstat 2 

iostat -ykx sda -d 2

-d displays the statistics every 2 seconds
-k displays the statistics in kilobytes
sda is the partition that we are interested in displaying its statistics
-y to omit first report with statistics since the system boot
-x to display more information

PT - Monitoring PS command

 Monitoring Processes through PS command 

• ps -ef 

• PS command contains CPU cloumns

ps aux

• Top 10 process consuming CPU

ps aux | sort -nrk 3,3 | head -n 10

• Top10 process consuming CPU

 ps -e -o pcpu,pid,user,tty,args | sort -n -k 1 -r | head -n 10

PT - OS TOP Monitoring commands

 

PT - OS TOP commands Monitoring 

Top Command Header 

Top  | users | load average | Tasks | cpu  | Memory | swapping 

Field/Section	Meaning
load average	This line displays the load averages over the last 1, 5 and 15 minutes. The higher the load average, the more work the machine is doing. A high rise in the load average could indicate a serious performance problem.
Tasks	Number of processes that are running, sleeping, stopped, or zombie. In a healthy system, this number does not change a lot by time.
Cpu(s)	CPU% usage by user (%us), system (%sy), nice (%ni), idle (%id), I/O wait (%wa), Hard Interrupt (%hi), soft interrupt (%si), and iosteal (%st) which is used in VM environments. Note: in top output, %wa is the only I/O load indicator.
Mem	Total physical memory, used memory, and free memory.
Swap	Information about swapping.
PID	Process Id. Used to know the relationship between the processes and for killing processes
USER	The effective user name of the task’s owner.
PR	Process priority
NI	Process nice value
VIRT	Total virtual memory used by the process
RES	Non-swapped physical memory used
SHR	Shared memory used by the process
S	Process status
%CPU	Processes percent of CPU consumption since last screen refresh
%MEM	Percentage of memory consumption by the process
TIME+	Total CPU time, showing hundredths of seconds
COMMAND	Command used to start the process

Key	Impact
[Shift]+[O]	Sort by a selected field (try sorting by memory, swapped size, command name)
[Shift]+[P]	Sort processes as per CPU utilization
z	highlight running processes. Press again to disable it.
c	Display the absolute path of running processes
d	Change screen refresh interval (by default it is 3)
k	Kill a process by its PID
q	Quit

• Top command based on particular user 

top -u oracle

• Display first 20 line output.

top -bc | head -20 display first 20 lines 

• Display order by memory usage 

top -bc -a | head -n 20 

• Enter Z  highlighting current running process.