Monitoring system swap space

2 minute read

Posted 2021-07-01 - Updated 2021-07-05
Supported on Linux, Aix, MacOS

Monitoring the Swap Space

To monitor a system swap space with SysMon, you must insert a line in SysMon configuration file ($SADMIN/cfg/hostname-s.smon) like the one below. The line MUST begin with the string “swap_space”.
In the example below, the current swap usage is at 3%, the “Warning” threshold is set to 85% and “Error” at 90%. If the percentage of utilization is greater or equal than one of these value then the “Warning” alert group “wargrp” or the “Error” alert group “errgrp” will get alerted. {: .text-justify}sysmon_warning_group

# ID COLUMN 1  2  3   4   5   6  7    8   9 A B C D E F G     H     I     J       K   L
swap_space     3  >  85  90 000 0000 0000 Y Y Y Y Y Y Y Y 00000000 0000 wargrp errgrp -
  • Every time a “swap_space” line is process by the System Monitor, it used the “free | grep -i swap” command (on MacOS ‘sysctl vm.swapusage’) to get a snapshot of the swap space utilization. The resultant value is then compare with the “Warning” and “Error” threshold specified respectively in column 4 and 5.
  • If the usage percentage is greater or equal (test in column 3) than the “Warning” or “Error” threshold value, then the “Warning” alert group (Column J) or “Error” alert group (Column K) will get alerted depending on which value is exceeded.


Example of SysMon output

In the example below the Swap Space utilization percentage is at 1%, no need to trigger an alert.

Creating lock file /opt/sadmin/sysmon.lock
Loading SADMIN configuration file /opt/sadmin/cfg/sadmin.cfg
------------------------------------------------------------------------------
SADMIN SYStem MONitor Tools - Version 2.44
------------------------------------------------------------------------------
O/S Name                 = linux
Debugging Level          = 5
SADM_BASE_DIR            = /opt/sadmin
Hostname                 = borg
Virtual Server           = N
CMD_SSH                  = /usr/bin/ssh
------------------------------------------------------------------------------

Loading SysMon configuration file /opt/sadmin/cfg/borg.smon
File /opt/sadmin/cfg/borg.smon loaded in sysmon_array (252 lines loaded)

Checking for new filesystems ...
No new filesystem detected

Checking CPU Load Average ...
Uptime line:  09:08:03 up 21:47,  1 user,  load average: 0.60, 1.34, 1.63
Load Average is at 0 - W: 20 E: 35

Checking CPU Usage ...
CPU Usage line: 0 0 211712 275768 593136 1527376 0 0 0 300 6148 10373 3 11 85 0 0

CPU User:   3 - System:  11  - Total:  14
 - Warning Level: 85 - Error Level: 95

Checking Swap Space ...
Swap Info Line: Swap:      16777204      211712    16565492
Swap size: 16777204 - Usage: 211712 - Percentage use: 1 %
...
...

Back to the top

See also

Link to … Description
sadm_sysmon_tui.pl Command line summary of alerts and failed scripts of all your servers.
sadm_sysmon.pl Client system monitor
sadm_fetch_clients.sh rsync all .rch/.log/.rpt from actives clients to the SADMIN server
SysMon configuration file Client System Monitor configuration file
sadmin.cfg SADMIN main configuration file

You may also enjoy