Glances: installing and tuning default thresholds on RedHat ES6

Glances is a free (under LGPL license) tool, written by Nicolas HENNION (aka Nicolargo) in Python and using libstatgrab to monitor your system.

I like the concept and it’s very easy to install and to handle.

I used to work a lot with top and sar on linux but now if I have the opportunity to install Glances, I do it.

Conceptually Glances is more like nmon on AIX, or glance on HP-UX (quite the same name, what a coincidence?).

Installation:

Download Glances (1.3.7 on this post) :

Compile glance (you will need gcc) :

# tar ztf glances-1.3.7.tar.gz
# cd glances-1.3.7/
# ./configure
# make
# make install

Then install libstatgrab and pystatgrab librairies.

# rpm -Uvh libstatgrab-0.15-1.el6.rf.x86_64.rpm
# rpm -Uvh pystatgrab-0.5-9.el6.x86_64.rpm

You will not found the 2 rpm on RH ES6 CDs but you can find them on rpm.pbone.net for instance.

Don’t try to install pystatgrab from the sources: it won’t work as it uses pkg-config and pkg-config is not able to locate the libs on RedHat (don’t now why?).

Run Glances:

# glances.py

From the screenshot one can see that the server’s main statistics are available on one screen:

Cpu, load, Memory, Network, Disk I/O, Disk space, and process

For the monitoring part you have colors for current thresholds overflow and an history of the last 3 to 10 warning and critical alerts.

For more information see the man page or Nicolargo’s web site (in French):

If you want to change the default limits, you will have to edit glances.py

# locate glances.py
/usr/local/bin/glances.py
# vi /usr/local/bin/glances.py

Find glancesLimits class :

class glancesLimits():
"""
Manage the limit OK,CAREFUL,WARNING,CRITICAL for each stats
"""
# The limit list is stored in an hash table:
#  limits_list[STAT] = [ CAREFUL , WARNING , CRITICAL ]
# Exemple:
#  limits_list['STD'] = [ 50, 70 , 90 ]
 
__limits_list = {   #           CAREFUL WARNING CRITICAL
'STD':  [50,    70,     90],
'LOAD': [0.7,   1.0,    5.0]
}

And modify the default limits, for instance:

__limits_list = {   #           CAREFUL WARNING CRITICAL
'STD':  [40,    50,     70],
'LOAD': [0.2,   0.5,    1.0]

Now you can see that while cpu% user if still lower than 90, the color is now red, meaning CRITICAL and the process who were in CAREFUL state before (<70) are now in WARNING state. Same comment on the load.