Resource Monitoring

All systems have the following resources available:

• CPU power
• Bandwidth
• Memory
• Storage

Purpose of Resouce mornitoring:
+ System have problem, can we improve its performence? (system performence monitoring)
+ System run well now, can we keep it later? (monitoring system capacity)

• System performence monitoring

• Determine the cause of problem
• Analyze the the data that produced from monitoring, to solve the problem
• Ensure the performence problem has been resolved
  

• Monitoring system capacity

Monitoring CPU Power
Monitoring Bandwidth
Monitoring Memory
Monitoring Storage
Tools for resource monitoring
free
Display amount of free and used memory in the system
# free
total used free shared buffers cached
Mem: 1023368 966064 57304 0 24704 247628
-/+ buffers/cache: 693732 329636
Swap: 2031608 164 2031444

Mem row: displays the physical memory utilization.
Swap row: displays the utilization of the system swap space.
+/- buffers/cache row: display the amount of physical memory currently devoted to system buffers.
to view it change with time using
#watch free
#watch -n 1 -d free
-n to set delay time, -d to highline the change

top
Display a lot of things.
#top
#gnome-system-monitor
vmstat
To get an overview of process, memory, swap, I/O, system, and CPU activity in one line of numbers:
# vmstat
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 164 68416 10204 251848 0 0 47 38 1121 1038 8 2 89 1 0
Procs
r: The number of runnable processes waiting for access to the CPU
b: The number of processes in an uninterrupible sleep state
Memory
swpd: The amount of virtual memory used
free: The amount of free memory
buff: The amount of memory used for buffers
cache: The amount of memory used as page cache
Swap
si: The amount of memory swapped in from disk
so: The amount of memory swapped out to disk
IO
bi: Blocks sent to a block device
bo: Blocks received from a block device
System
in: The number of interrupts per second
cs: The number context switches per second
CPU
us: The percentage of the time the CPU ran user-level code
sy: The percentage of the time of CPU ran system-level code
id: The percentage of the time the CPU was idle
wa: The percentage of the time spent running non-kernel code
st: The percentage of the time stolen from a virtual machine
The Sysstat Suite of Resource Monitoring Tools
#yum -y install sysstat.i386
iostat
Display an overview of CPU utilization, along with I/O statistics for one or more disk devices
mpstat
Display more in-depth CPU statistics.
sadc (/usr/lib/sa/sadc), sar generate the reports interactively.