Changes in envsys2 include use of proplib(3) for communication betwen kernel and user space, attaching and detaching of sensors and a rewrite of envstat(8) to specify limits, descriptions and other values in /etc/envsys.conf. Furthermore, there's an 'envsys' rc.d script now to set parameters in batch mode. The 'envsys' rc.d script is a wrapper around the new envstat(8) command, which Juan also rewrote from scratch.

When compared against other frameworks for monitoring sensors and environmental state, one difference is that envsys does the polling in the kernel instead of userland, leading to less overhead. Furthermore, changing of descriptions, resistor factors for voltage sensors and capacity limits for battery sensors are now available to be set via envstat(8). Also some drivers like acpibat(8) and acpitz(8) were adapted to envsys2 and now they send events when a critical state happens, please see the new powerd(8) manpage for more information. Envsys2 supports enabling monitoring in sensors directly on the driver, without user interaction (these events cannot be disabled either). E.g. with the sensor_drive and a driver that uses the feature, it is possible to be notified when a drive in a hardware RAID is not in a normal state.

For more information see Juan's mail, or have a look at the updated manpages. For more details, there's also a README that describes the internal file format.

[Tags: envsys]