Jon agent throws "Too many Sigar instances created" exception

Issue

• JON agent throws runtime Exception when NFS went down

java.lang.RuntimeException: Too many Sigar instances created
        at org.rhq.core.system.SigarAccessHandler.createLocalSigarInstance(SigarAccessHandler.java:150)
        at org.rhq.core.system.SigarAccessHandler.invoke(SigarAccessHandler.java:135)
        at com.sun.proxy.$Proxy40.getMountedFileSystemUsage(Unknown Source)
        at org.rhq.core.system.FileSystemInfo.refresh(FileSystemInfo.java:60)
        at org.rhq.core.system.FileSystemInfo.<init>(FileSystemInfo.java:43)
        at org.rhq.core.system.NativeSystemInfo.getFileSystem(NativeSystemInfo.java:342)
        at org.rhq.plugins.platform.FileSystemComponent.getFileSystemInfo(FileSystemComponent.java:95)
        at org.rhq.plugins.platform.FileSystemComponent.getAvailability(FileSystemComponent.java:61)
        at org.rhq.core.pc.inventory.AvailabilityProxy.call(AvailabilityProxy.java:143)
        at org.rhq.core.pc.inventory.AvailabilityProxy.call(AvailabilityProxy.java:52)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)