System Information Binding

The System Information binding provides operating system monitoring data, including system memory, swap, CPU, load average, uptime, per-process memory, per-process CPU, file system metrics and network interface metrics.

The binding uses the Hyperic SIGAR API to access system information regardless of the underlying platform (Windows, Linux, OS X…).

There is also a binding specifically for openHAB 2 here.

Table of Contents

Binding Configuration

This binding can be configured in the file services/systeminfo.cfg.

Property Default Required Description
granularity 1000 No Interval in milliseconds when to find new refresh candidates
units M No Data Storage Unit, where B=Bytes, K=kB, M=MB, T=TB
variant   required for ARM/Linux or custom, not required for standard platforms Alternative native library to load. Choices for ARM/Linux are cubian, odroid-u3 or raspbian. This results in loading a native library having the name [lib]sigar-<variant>[.so|.sl|.dll|.dylib]

Hyperic SIGAR Native libraries

The SIGAR native libraries for standard platforms (and cubian, odroid-u3 and raspbian ARM/Linux systems) are included and loaded automatically by the binding. To use a platform-specific native library that is not included in the binding JAR, place it in your lib folder and make sure it is named as described above in the instructions for the variant configuration property.

Item Configuration

The syntax of the binding configuration strings accepted is the following:



  • <commandType> corresponds to the command type. See complete list below. Note that the output of some commands (eg. DirUsage) will be affected by filesystem permissions. ie. Directories that the process is not permitted access to cannot be include in the tally.

  • <refreshPeriod> corresponds to the update interval of the item in milliseconds.

  • <target> corresponds to the target of the command. Target field is mandatory only for commands, which need target. See further details from supported command list below.

Command Item Type Purpose Note
CpuCombined Number    
CpuNice Number    
CpuSystem Number    
CpuUser Number    
CpuWait Number    
DirFiles Number   target = directory path (if folder contains lot of files scan can take a while!)
DirUsage Number   target = directory path (if folder contains lot of files scan can take a while!)
DiskReadBytes Number   target = disk name (2)
DiskReads Number   target = disk name (2)
DiskWriteBytes Number   target = disk name (2)
DiskWrites Number   target = disk name (2)
FileSystemFiles Number   target = name of the directory on which filesystem is mounted
FileSystemFree Number   target = name of the directory on which filesystem is mounted
FileSystemFreeFiles Number   target = name of the directory on which filesystem is mounted
FileSystemTotal Number   target = name of the directory on which filesystem is mounted
FileSystemUsagePercent Number   target = name of the directory on which filesystem is mounted
FileSystemUsed Number   target = name of the directory on which filesystem is mounted
LoadAverage15Min Number    
LoadAverage1Min Number    
LoadAverage5Min Number    
MemActualFree Number    
MemActualUsed Number    
MemFree Number    
MemFreePercent Number    
MemTotal Number    
MemUsed Number    
MemUsedPercent Number    
NetRxBytes Number   target = net interface name (1)
NetTxBytes Number   target = net interface name (1)
ProcessCpuPercent Number   target = process name (3)
ProcessCpuPercent Number   target = process name (3)
ProcessCpuSystem Number   target = process name (3)
ProcessCpuTotal Number   target = process name (3)
ProcessCpuUser Number   target = process name (3)
ProcessRealMem Number   target = process name (3)
ProcessUptime Number   target = process name (3)
ProcessUptimeFormatted String   target = process name (3)
ProcessVirtualMem Number   target = process name (3)
SwapFree Number    
SwapPageIn Number    
SwapPageOut Number    
SwapTotal Number    
SwapUsed Number    
Uptime Number    
UptimeFormatted String    


  • (1) interface name:

Check supported interface names by ifconfig, ipconfig or openhab debug log E.g. “21:56:12.930 DEBUG o.o.b.s.internal.SysteminfoBinding[- valid net interfaces: lo0, en0, en1, p2p0, vboxnet0

  • (2) disk name:

Check supported disk names by iostat or openhab debug log “21:56:12.931 DEBUG o.o.b.s.internal.SysteminfoBinding[- valid disk names: /dev/disk0s2

  • (3) process name supports:
Usage Example Explanatory
$$ $$ current process
processname eclipse process name contains “eclipse”
**processname **eclipse process name ends to “eclipse”
processname** eclipse** process name start with “eclipse”
=processname =eclipse process name equals “eclipse”
#PTQL #State.Name.eq=eclipse Sigar Process Table Query Language



Group System
Number loadAverage1min  "Load avg. 1min [%.1f]" (System) { systeminfo="LoadAverage1Min:5000" }
Number loadAverage5min  "Load avg. 5min [%.1f]" (System) { systeminfo="LoadAverage5Min:5000" }
Number loadAverage15min "Load avg. 15min [%.1f]"    (System) { systeminfo="LoadAverage15Min:5000" }

Number cpuCombined  "CPU combined [%.1f]"   (System) { systeminfo="CpuCombined:5000" }
Number cpuUser  "CPU user [%.1f]"   (System) { systeminfo="CpuUser:5000" }
Number cpuSystem    "CPU system [%.1f]" (System) { systeminfo="CpuSystem:5000" }
Number cpuNice  "CPU nice [%.1f]"   (System) { systeminfo="CpuNice:5000" }
Number cpuWait "CPU wait [%.1f]"    (System) { systeminfo="CpuWait:5000" }

Number uptime   "Uptime [%.1f]" (System) { systeminfo="Uptime:5000" }
String uptimeFormatted  "Uptime [%s]" (System) { systeminfo="UptimeFormatted:5000" }

Number memFreePercentPeriod "MemFree chart selected [%.1f]" (System)
Number memFreePercent   	"Mem free [%.1f%%]" (System) { systeminfo="MemFreePercent:5000" }
Number memUsed  			"Mem used [%.1f]"   (System) { systeminfo="MemUsed:5000" }
Number memUsedPercent   	"Mem used [%.1f%%]" (System) { systeminfo="MemUsedPercent:5000" }
Number memActualFree    	"Mem actual free [%.1f]"    (System) { systeminfo="MemActualFree:5000" }
Number memActualUsed    	"Mem actual used [%.1f]"    (System) { systeminfo="MemActualUsed:5000" }
Number memTotal 			"Mem total [%.1f]"  (System) { systeminfo="MemTotal:5000" }

Number swapFree "Swap free [%.1f]"  (System) { systeminfo="SwapFree:5000" }
Number swapTotal    "Swap total [%.1f]" (System) { systeminfo="SwapTotal:5000" }
Number swapUsed "Swap used [%.1f]"  (System) { systeminfo="SwapUsed:5000" }
Number swapPageIn   "Swap pagein [%.1f]"    (System) { systeminfo="SwapPageIn:5000" }
Number swapPageOut  "Swap pageout [%.1f]"   (System) { systeminfo="SwapPageOut:5000" }

Number netTxBytes   "Next tx bytes [%.1f]"  (System) { systeminfo="NetTxBytes:5000:en1" }
Number netRxBytes   "Next rx bytes [%.1f]"  (System) { systeminfo="NetRxBytes:5000:en1" }

Number diskReads    "Disk reads [%.1f]" (System) { systeminfo="DiskReads:5000:/dev/disk1" }
Number diskWrites   "Disk writes [%.1f]"    (System) { systeminfo="DiskWrites:5000:/dev/disk1" }
Number diskReadBytes    "Disk read bytes [%.1f]"    (System) { systeminfo="DiskReadBytes:5000:/dev/disk1" }
Number diskWriteBytes   "Disk write bytes [%.1f]"   (System) { systeminfo="DiskWriteBytes:5000:/dev/disk1" }

Number dirUsage "Dir usage [%.1f]"  (System) { systeminfo="DirUsage:5000:/Users/foo" }
Number dirFiles "Dir files [%.1f]"  (System) { systeminfo="DirFiles:5000:/Users/foo" }

Number openhabRealMem   "Real mem [%.1f]"   (System) { systeminfo="ProcessRealMem:5000:$$" }
Number openhabVirtualMem    "Virtual mem [%.1f]"    (System) { systeminfo="ProcessVirtualMem:5000:$$" }
Number openhabCpuPercent    "Cpu percent [%.1f%%]"  (System) { systeminfo="ProcessCpuPercent:5000:$$" }
Number openhabCpuSystem "CPU system [%.1f]" (System) { systeminfo="ProcessCpuSystem:5000:$$" }
Number openhabCpuUser   "CPU user [%.1f]"   (System) { systeminfo="ProcessCpuUser:5000:$$" }
Number openhabCpuTotal  "CPU total [%.1f]"  (System) { systeminfo="ProcessCpuTotal:5000:$$" }
Number openhabUptime    "Uptime [%d]"   (System) { systeminfo="ProcessUptime:5000:$$" }
String openhabUptimeFormatted   "Uptime form. [%s]" (System) { systeminfo="ProcessUptimeFormatted:5000:$$" }

Number eclipseRealMem1  "Real mem1 [%.1f%%]"  (System) { systeminfo="ProcessCpuPercent:10000:eclipse" }
Number eclipseRealMem2  "Real mem2 [%.1f%%]"  (System) { systeminfo="ProcessCpuPercent:10000:*eclipse" }
Number eclipseRealMem3  "Real mem3 [%.1f%%]"  (System)  { systeminfo="ProcessCpuPercent:10000:eclipse*" }
Number eclipseRealMem4  "Real mem4 [%.1f%%]"  (System) { systeminfo="ProcessCpuPercent:10000:=eclipse" }
Number eclipseRealMem5  "Real mem5 [%.1f%%]"  (System) { systeminfo="ProcessCpuPercent:10000:#State.Name.eq=eclipse" }


Frame {
	Group item=System label="System Info" icon="system" {
		Frame {
			Text item=uptime
			Text item=cpuCombined icon="system"
		Frame label="Load" {
			Text item=loadAverage1min
			Text item=loadAverage5min
			Text item=loadAverage15min
		Frame label="Memory" {
			Text item=memFreePercent  {
				Frame {
					Switch item=memFreePercentPeriod label="Periode" mappings=[0="Time", 1="Dag", 2="Uke"]
					Chart item=memFreePercent period=h refresh=30000 visibility=[memFreePercentPeriod==0, memFreePercentPeriod=="Uninitialized"]
					Chart item=memFreePercent period=D refresh=30000 visibility=[memFreePercentPeriod==1]
					Chart item=memFreePercent period=W refresh=30000 visibility=[memFreePercentPeriod==2]
			Text item=memUsed 
			Text item=memUsedPercent
			Text item=memActualFree 
			Text item=memActualUsed 
			Text item=memTotal 
		Frame label="Swap" {
			Text item=swapFree 
			Text item=swapTotal
			Text item=swapUsed 
		Frame label="Openhab" {
			Text item=openhabRealMem
			Text item=openhabVirtualMem
			Text item=openhabCpuPercent
			Text item=openhabCpuSystem
			Text item=openhabUptime
			Text item=openhabUptimeFormatted

Raspberry Pi System Temperature

Although unrelated to the System Information binding, you can augment the capability of this binding using other add-ons.


  • openHAB has been installed on Raspberry Pi
  • The Exec 1.x Binding has been installed
  • RRD4J Persistence has been installed
  • The JavaScript transformation service has been installed
  • User openhab is member of the video group

The user openhab needs to be member of the video group to be able to run the vcgencmd command. Otherwise you will see a VCHI initialization failed error message.

The effect of this group membership is only taken after a reboot.

$ sudo usermod -a -G video openhab
$ sudo reboot


This solution was developed for a Raspberry Pi 2 model B running Raspbian) and an “apt-get” installation of openHAB.

The temperatures for both CPU and GPU can be read through terminal commands:

$ cat /sys/class/thermal/thermal_zone0/temp
$ /opt/vc/bin/vcgencmd measure_temp

This means the output can be captured using the Exec Binding.

However, the CPU temperature is returned as millidegrees Celsius. The GPU temperature has some surrounding text for readability. Both need some transformations to get the values into openHAB properly.

The CPU temperature is computed through a Javascript transformation. The GPU temperature is captured through a Regex transformation.

This example gets the CPU temperature in degrees Celsius every 60 seconds and persistently stores them for presenting in a graph. It assumes that all items containing system information (potentially including those for the System Information Binding) are in a systems.items file (any other items file will do).

Example configuration

Create a transform/milli.js file with this content:

(function(i){ return i / 1000; })(input)

Add to items/system.items file:

// System temperatures
Group  System_Temperature_Chart (System, Charts)
Number System_Temperature_Chart_Period "Periode" (System)
Number System_Temperature_CPU "Temperature CPU [%.1f °C]" <temperature> (System_Temperature_Chart) { exec="<[cat /sys/class/thermal/thermal_zone0/temp:60000:JS(milli.js)]" }
Number System_Temperature_GPU "Temperature GPU [%.1f °C]" <temperature> (System_Temperature_Chart) { exec="<[/opt/vc/bin/vcgencmd measure_temp:60000:REGEX(temp=(.*?)'C)]" }

Add to rrd4j.persist file:

System_Temperature_Chart* : strategy = everyChange, everyMinute, restoreOnStartup

Add to sitemaps/default.sitemap file:

Text item=System_Temperature_CPU label="Temperature [%.1f °C]" {
	Frame {
		Text item=System_Temperature_CPU					
		Text item=System_Temperature_GPU
	Frame {
		Switch item=System_Temperature_Chart_Period mappings=[0="1h", 1="4h", 2="8h", 3="12h", 4="24h"]
		Chart  item=System_Temperature_Chart period=h   refresh=60000 visibility=[System_Temperature_Chart_Period==0, System_Temperature_Chart_Period=="Uninitialized"]
		Chart  item=System_Temperature_Chart period=4h  refresh=60000 visibility=[System_Temperature_Chart_Period==1]
		Chart  item=System_Temperature_Chart period=8h  refresh=60000 visibility=[System_Temperature_Chart_Period==2]
		Chart  item=System_Temperature_Chart period=12h refresh=60000 visibility=[System_Temperature_Chart_Period==3]
		Chart  item=System_Temperature_Chart period=D   refresh=60000 visibility=[System_Temperature_Chart_Period==4]